Ecological and molecular insights into the function of colourful signals in aquatic environments

Discovering the processes that drive the emergence of new species and connecting it to biodiversity in its past, present, and future form has been one of the central questions of natural scientists for over a century. Two ways in which we can start to unravel the mechanisms that have created such diversity is to investigate: 1) the selective pressures that can initiate/drive and 2) the molecular capacities allowing evolutionary changes to happen. A convenient approach to study how environmental cues and molecular processes are linked to appearance is by investigating the emergence of similar phenotypes, whether they evolve in response to likewise selective pressures and/or in response to molecular or developmental constraints. Here, mimics because they imitate unrelated species (the model), are a classical example in which to study phenotypic convergence. CHAPTER1 (Published in Current Biology, 2015); Using a combination of behavioural, cell histological, neurophysiological and molecular approaches, the first chapter of my PhD thesis aimed to uncover the triggers for colour change in a small coral reef fish mimic, the dottyback, Pseudochromis fuscus. Yellow morphs are mainly found on live coral in association with yellow damselfish species such as the ambon- (Pomacentrus amboinensis) and the lemon damselfish (P. moluccensis), while brown morphs occur mainly on coral rubble in association with brown damselfishes such as the whitetail damselfish (P. chrysurus). Potential environmental cues that could be associated with colour change therefore included: i) aggressive mimicry, dottyback morphs associate with similarly coloured damselfishes to increase foraging success by preventing detection by juvenile fish prey; ii) social mimicry, differently coloured morphs hide among similarly coloured damselfish to reduce detection and predation risk from their own predators; and iii) crypsis, different coloured morphs match the colour of their background habitat to prevent detection from predators or potential prey. CHAPTER 2 (Published in The Journal of Experimental Biology, 2016); The second chapter aimed at investigating the triggers for ontogenetic colour changes and how these interrelate to the development of the visual system in dottybacks. Although adult dottybacks were found to be aggressive mimics that change colour to impersonate the colouration of the prevalent damselfish community, little was known about the early life stages of this fish. Using a developmental time series in combination with wild caught dottyback specimens I show multiple colour changes during dottyback ontogeny and link them to crucial life history transitions of dottybacks. Moreover, changes in the visual system were found to precede ontogenetic colour changes, and theoretical fish visual models were subsequently used to investigate the potential benefits of this pattern. CHAPTER 3 (Published in PNAS, 2015); Work for chapter 3 was done in collaboration with Dr. Zuzana Musilová at the University of Basel and was based on the discovery of multiple novel visual genes (opsins) in the dottyback (Chapter 2), which arose through gene duplications. One of these novel gene duplicates was found in the violet-blue opsin sub-family (SWS2); however, initial reconstruction of the SWS2 phylogeny suggested a much older, non- dottyback specific origin of the duplication event. Therefore, in chapter three we performed a thorough investigation of SWS2 by exploring the evolutionary history of this family in close to 100 fish species representing most fish lineages across the modern fish phylogeny

Information Flow Analysis for Detecting Non-Determinism in Blockchain

A mandatory feature for blockchain software, such as smart contracts and decentralized applications, is determinism. In fact, non-deterministic behaviors do not allow blockchain nodes to reach one common consensual state or a deterministic response, which causes the blockchain to be forked, stopped, or to deny services. While domain-specific languages are deterministic by design, general purpose languages widely used for the development of smart contracts such as Go, provide many sources of non-determinism. However, not all non-deterministic behaviours are critical. In fact, only those that affect the state or the response of the blockchain can cause problems, as other uses (for example, logging) are only observable by the node that executes the application and not by others. Therefore, some frameworks for blockchains, such as Hyperledger Fabric or Cosmos SDK, do not prohibit the use of non-deterministic constructs but leave the programmer the burden of ensuring that the blockchain application is deterministic. In this paper, we present a flow-based approach to detect non-deterministic vulnerabilities which could compromise the blockchain. The analysis is implemented in GoLiSA, a semantics-based static analyzer for Go applications. Our experimental results show that GoLiSA is able to detect all vulnerabilities related to non-determinism on a significant set of applications, with better results than other open-source analyzers for blockchain software written in Go

Information Flow Analysis for Detecting Non-Determinism in Blockchain (Artifact)

A mandatory feature for blockchain software, such as smart contracts and decentralized applications, is determinism. In fact, non-deterministic behaviors do not allow blockchain nodes to reach one common consensual state or a deterministic response, which causes the blockchain to be forked, stopped, or to deny services. While domain-specific languages are deterministic by design, general-purpose languages widely used for the development of smart contracts such as Go, provide many sources of non-determinism. However, not all non-deterministic behaviours are critical. In fact, only those that affect the state or the response of the blockchain can cause problems, as other uses (for example, logging) are only observable by the node that executes the application and not by others. Therefore, some frameworks for blockchains, such as Hyperledger Fabric or Cosmos SDK, do not prohibit the use of non-deterministic constructs but leave the programmer the burden of ensuring that the blockchain application is deterministic. In this paper, we present a flow-based approach to detect non-deterministic vulnerabilities which could compromise the blockchain. The analysis is implemented in GoLiSA, a semantics-based static analyzer for Go applications. Our experimental results show that GoLiSA is able to detect all vulnerabilities related to non-determinism on a significant set of applications, with better results than other open-source analyzers for blockchain software written in Go

Regulation, constraints and benefits of colour plasticity in a mimicry system

Rapid colour change is used in aggressive interactions, ontogenetic transitions, nuptial displays and to prevent detection and/or recognition from predators or prey. The underlying mechanisms, constraints and benefits of colour change are often unclear, but examining such factors offers insights into phenotypic plasticity. Here, we investigated the mechanisms behind how an aggressive reef fish mimic (bluestriped fangblenny Plagiotremus rhinorhynchos) changes colour rapidly (1-5 min) between mimetic and other colour forms. Black with one neon blue dorsal stripe (mimic), black with two neon blue stripes, brown, olive and orange forms differed in melanophore density. Fish skin biopsies were modulated in vitro by hormones, and smaller fangblennies changed coloration more rapidly than larger fish suggesting that the ability to change colour is diminished as fish get larger. Individuals may be limited by differences in pigment cell densities to change colour between extreme colour forms (black to orange); therefore, longer morphological changes may also occur or fangblennies may exhibit dimorphic populations. Behavioural observations suggest that small black and orange individuals were equally successful in attacking passing fish to feed on dermal tissue/scales, indicating that deceptive strategies used by each colour form may deliver equal fitness benefits. The present study demonstrates for the first time how fangblennies change colour and highlights that colour plasticity offers important adaptive advantage; however, physiological constraints should also be considered

Morphological and Optical Modification of Melanosomes in Fish Integuments upon Oxidation

Reactive oxygen species (ROS) such as superoxide radicals O2−, hydroxyl radicals OH−, and hydrogen peroxide H2O2 may have detrimental effects on marine organisms, including their integuments and visual appearances. Although some studies have described the impact of ROS on marine ecosystems and species ecology, the influence on the optical response of the integuments of marine species and on their visual appearances remains unknown. In this article, we used histology and optical characterisation to show, for the first time, that skin melanophores (melanin-containing chromophores) of the coral reef fish, Stegastes apicalis, change their shapes and fluorescent proprieties upon oxidation with H2O2 radicals. Our observations also suggest that pheomelanosomes may occur in fish integuments, where, previously, it was thought that fish melanosomes only contain eumelanin. This investigation relied on light and electron microscopy and steady-state fluorimetry, as well as time-resolved streak imaging systems. We suggest that the changes in the morphological and spectral characteristics of melanophores can be used as a marker of physiological stress induced by environmental factors such as ROS. Moreover, S. apicalis may be used as a potential model for studying the interaction between the surrounding environment and natural organisms in biologically diverse ecosystems, such as the Great Barrier Reef in Australia

BRCA mutation carriers' perceptions on postmenopausal hormone therapy: An Italian study

Objective To evaluate the actual perceptions of postmenopausal hormone therapy (HT) in BRCA mutation carriers (BRCAmc) in comparison with women from the general population.Methods Questionnaire-based study of 83 BRCAmc and a control group of 89 women without a genetic mutation. Perceptions were evaluated by specific questions and Likert scales (-5-+5).Results Present and past users of HT were more frequent in the control group (p = 0.01), with a longer time of use (p = 0.03). The preferred route of administration of HT was 'oral' (54.6%). The most frequently reported adverse effect of HT was venous thrombosis (0.8), while a protective effect on bone health was reported. No noticeable beneficial effects of HT have been recognised for hot flushes (0.2) and vaginal dryness (0.1). The most frequently perceived beneficial and adverse effects of HT were not significantly different between BRCA mutation carriers and controls. The greatest oncological fear was breast cancer (1.0). The protective role of HT on colorectal cancer was not known (0.1). These oncological impacts were mostly overestimated in BRCAmc, however this was not significant. Few BRCAmc would think of taking HT after risk-reducing surgeries.Conclusions Knowledge of the effects of HT on BRCAmc is relatively poor and they are likely to overstate its negative effects and underestimate its health benefits; however, this is not significant in comparison to the general population. More and better information should be given to BRCAmc to allow them to make informed decisions about the use of HT, especially before undergoing risk-reducing surgeries

Variation of anal fin egg-spots along an environmental gradient in a haplochromine cichlid fish

Male secondary sexual traits are targets of inter- and/or intrasexual selection, but can vary due to a correlation with life-history traits or as by-product of adaptation to distinct environments. Trade-offs contributing to this variation may comprise conspicuousness towards conspecifics versus inconspicuousness towards predators, or between allocating resources into coloration versus the immune system. Here, we examine variation in expression of a carotenoid-based visual signal, anal-fin egg-spots, along a replicate environmental gradient in the haplochromine cichlid fish Astatotilapia burtoni. We quantified egg-spot number, area, and coloration; applied visual models to estimate the trait's conspicuousness when perceived against the surrounding tissue under natural conditions; and used the lymphocyte ratio as a measure for immune activity. We find that (i) males possess larger and more conspicuous egg-spots than females, which is likely explained by their function in sexual selection; (ii) riverine fish generally feature fewer but larger and/or more intensively colored egg-spots, which is probably to maintain signal efficiency in intraspecific interactions in long-wavelength shifted riverine light conditions; and (iii) egg-spot number and relative area correlate with immune defense, suggesting a trade-off in the allocation of carotenoids. Taken together, haplochromine egg-spots feature the potential to adapt to the respective underwater light environment, and are traded-off with investment into the immune syste

Phase II study of liposomal doxorubicin, docetaxel and trastuzumab in combination with metformin as neoadjuvant therapy for HER2-positive breast cancer

Background:The aim of this study was to improve activity over single human epidermal growth factor receptor 2 (HER2)-blockade sequential neaodjuvant regimens for HER2-positive breast cancer, by exploiting the concomitant administration of trastuzumab, taxane and anthracycline, while restraining cardiac toxicity with use of liposomal doxorubicin, and by adding metformin, based on preliminary evidence of antitumor activity.Patients and methods:This multi-center, single-arm, two-stage phase II trial, assessed the safety and the activity of a new treatment regimen for HER2-positive, early or locally advanced breast cancer. Patients received six 21-day cycles of non-pegylated liposomal doxorubicin, 50 mg/m(2) intravenously (i.v.) on day 1, docetaxel, 30 mg/m(2) i.v. on days 2 and 9, trastuzumab, 2 mg/kg/week i.v. on days 2, 9, and 16 (with 4 mg/kg loading dose), in association with metformin 1000 mg orally twice daily. The primary endpoint was the rate of pathological complete response (pCR) in the breast and axilla (ypT0/is ypN0). A subgroup of patients performed a 3-deoxy-3-18F-fluorothymidine positron emission tomography (FLT-PET) at baseline and after one cycle.Results:Among 47 evaluable patients, there were 18 pCR [38.3%, 95% confidence interval (CI) 24.5-53.6%]. A negative estrogen-receptor status, high Ki67, and histological grade 3 were related with pCR, although only grade reached statistical significance. FLT-PET maximum standardized uptake value after one cycle was inversely related to pCR in the breast (odds ratio 0.29, 95% CI 0.06-1.30, p = 0.11). Toxicity included grade 3-4 neutropenia in 70% and febrile neutropenia in 4% of patients, grade 1-2 nausea/vomiting in 60%/38%, and grade 3 in 4%/2%, respectively, grade 1-2 diarrhea in 72%, and grade 3 in 6%. There were two cases of reversible grade 2 left-ventricular ejection-fraction decrease, and one case of sharp troponin-T increase.Conclusions:The concomitant administration of trastuzumab, liposomal doxorubicin, docetaxel, and metformin is safe and shows good activity, but does not appear to improve activity over conventional sequential regimens

breast screening axillary lymph node status of interval cancers by interval year

Abstract The aim of this study was to determine whether the excess risk of axillary lymph node metastases (N+) differs between interval breast cancers arising shortly after a negative mammography and those presenting later. In a registry-based series of pT1a–pT3 breast carcinoma patients aged 50–74years from the Italian screening programmes, the odds ratio (OR) for interval cancers ( n =791) versus the screen-detected (SD) cancers ( n =1211) having N+ was modelled using forward stepwise logistic regression analysis. The interscreening interval was divided into 1–12, 13–18, and 19–24months. The prevalence of N+ was 28% among SD cancers. With a prevalence of 38%, 42%, and 44%, the adjusted (demographics and N staging technique) OR of N+ for cancers diagnosed between 1–12, 13–18, and 19–24months of interval was 1.41 (95% confidence interval 1.06–1.87), 1.74 (1.31–2.31), and 1.91 (1.43–2.54), respectively. Histologic type, tumour grade, and tumour size were entered in turn into the model. Histologic type had modest effects. With adjustment for tumour grade, the ORs decreased to 1.23 (0.92–1.65), 1.58 (1.18–2.12), and 1.73 (1.29–2.32). Adjusting for tumour size decreased the ORs to 0.95 (0.70–1.29), 1.34 (0.99–1.81), and 1.37 (1.01–1.85). The strength of confounding by tumour size suggested that the excess risk of N+ for first-year interval cancers reflected only their higher chronological age, whereas the increased aggressiveness of second-year interval cancers was partly accounted for by intrinsic biological attributes