Hansen Neuropathy: Still a Possible Diagnosis in the Investigation of a Peripheral Neuropathy

INTRODUCTION: Leprosy is still one of the most frequent causes of peripheral neuropathy. Although regarded as eradicated in Portugal, is still documented in neuropathological study of patients with clinical peripheral neuropathy without proper diagnosis.

An exploration of parent ivolvement in Response to Intervention (RTI) in Title I schools

Research demonstrates that parental involvement positively impacts student achievement and enhances targeted instruction. Notably, however, little research currently exists on how schools involve parents in Response to Intervention (RTI), a framework for implementing targeted, tiered, research-based instruction. The purpose of this study was to interview selected parents, teachers, RTI specialists, and principals in three Title I elementary schools in one school district, plus one district-level administrator, in order to examine how elementary schools currently involve parents in RTI prereferral interventions, and to understand the factors that might facilitate or challenge such parent involvement. I employed a comparative case study qualitative design with each elementary school as the main unit of analysis. I conducted individual, in-depth interviews that lasted approximately 45-60 minutes with a total of 33 participants across the three school sites, including 11 parents, 12 teachers, and six RTI specialists, three principals, and one district-level administrator. I also analyzed documents related to RTI processes that are available through websites and participants. I used Strauss and Corbin’s (1998) three-step scheme for thematic/grounded theory analysis, and Atlas.ti as the electronic tool for management and analysis. Analyses of the data revealed that personnel across the sites largely agreed on how they explain RTI to parents and notify parents of student progress. Parents mostly disagreed with these accounts, stating instead that they learn about RTI and their child’s progress by approaching teachers or their own children with questions, or by examining report cards and student work that comes home. Personnel and parents cited various challenges for involving parents in RTI. However, they all also agreed that teachers are accessible and willing to reach out to parents, and that teachers already face considerable workloads. It appears that no district- or school-wide plan guides parent involvement practices in RTI at any of the three schools. Finally, I present a discussion of findings; implications for teachers, RTI implementation leaders, and Title school leaders; study limitations; and possibilities for future research.

Using Habitat Equivalency Analysis to Assess the Cost Effectiveness of Restoration Outcomes in Four Institutional Contexts

At the national level, with a fixed amount of resources available for public investment in the restoration of biodiversity, it is difficult to prioritize alternative restoration projects. One way to do this is to assess the level of ecosystem services delivered by these projects and to compare them with their costs. The challenge is to derive a common unit of measurement for ecosystem services in order to compare projects which are carried out in different institutional contexts having different goals (application of environmental laws, management of natural reserves, etc.). This paper assesses the use of habitat equivalency analysis (HEA) as a tool to evaluate ecosystem services provided by restoration projects developed in different institutional contexts. This tool was initially developed to quantify the level of ecosystem services required to compensate for non-market impacts coming from accidental pollution in the US. In this paper, HEA is used to assess the cost effectiveness of several restoration projects in relation to different environmental policies, using case studies based in France. Four case studies were used: the creation of a market for wetlands, public acceptance of a port development project, the rehabilitation of marshes to mitigate nitrate loading to the sea, and the restoration of streams in a protected area. Our main conclusion is that HEA can provide a simple tool to clarify the objectives of restoration projects, to compare the cost and effectiveness of these projects, and to carry out trade-offs, without requiring significant amounts of human or technical resources.

Calibration and simulations of SIXS-P's response to energetic particles

The Solar Intensity X-ray and particle Spectrometer (SIXS) on board BepiColombo's Mercury Planetary Orbiter (MPO) will study solar energetic particles moving towards Mercury and solar X-rays on the dayside of Mercury. The SIXS instrument consists of two detector sub-systems; X-ray detector SIXS-X and particle detector SIXS-P. The SIXS-P subdetector will detect solar energetic electrons and protons in a broad energy range using a particle telescope approach with five outer Si detectors around a central CsI(Tl) scintillator. The measurements made by the SIXS instrument are necessary for other instruments on board the spacecraft. SIXS data will be used to study the Solar X-ray corona, solar flares, solar energetic particles, the Hermean magnetosphere, and solar eruptions. The SIXS-P detector was calibrated by comparing experimental measurement data from the instrument with Geant4 simulation data. Calibration curves were produced for the different side detectors and the core scintillator for electrons and protons, respectively. The side detector energy response was found to be linear for both electrons and protons. The core scintillator energy response to protons was found to be non-linear. The core scintillator calibration for electrons was omitted due to insufficient experimental data. The electron and proton acceptance of the SIXS-P detector was determined with Geant4 simulations. Electron and proton energy channels are clean in the main energy range of the instrument. At higher energies, protons and electrons produce non-ideal response in the energy channels. Due to the limited bandwidth of the spacecraft's telemetry, the particle measurements made by SIXS-P have to be pre-processed in the data processing unit of the SIXS instrument. A lookup table was created for the pre-processing of data with Geant4 simulations, and the ability of the lookup table to provide spectral information from a simulated electron event was analysed. The lookup table produces clean electron and proton channels and is able to separate protons and electrons. Based on a simulated solar energetic electron event, the incident electron spectrum cannot be determined from channel particle counts with a standard analysis method.

Applied evolution: An integrated approach to studying life history traits in response to drug selection

The use of chemical control measures to reduce the impact of parasite and pest species has frequently resulted in the development of resistance. Thus, resistance management has become a key concern in human and veterinary medicine, and in agricultural production. Although it is known that factors such as gene flow between susceptible and resistant populations, drug type, application methods, and costs of resistance can affect the rate of resistance evolution, less is known about the impacts of density-dependent eco-evolutionary processes that could be altered by drug-induced mortality. The overall aim of this thesis was to take an experimental evolution approach to assess how life history traits respond to drug selection, using a free-living dioecious worm (Caenorhabditis remanei) as a model. In Chapter 2, I defined the relationship between C. remanei survival and Ivermectin dose over a range of concentrations, in order to control the intensity of selection used in the selection experiment described in Chapter 4. The dose-response data were also used to appraise curve-fitting methods, using Akaike Information Criterion (AIC) model selection to compare a series of nonlinear models. The type of model fitted to the dose response data had a significant effect on the estimates of LD50 and LD99, suggesting that failure to fit an appropriate model could give misleading estimates of resistance status. In addition, simulated data were used to establish that a potential cost of resistance could be predicted by comparing survival at the upper asymptote of dose-response curves for resistant and susceptible populations, even when differences were as low as 4%. This approach to dose-response modeling ensures that the maximum amount of useful information relating to resistance is gathered in one study. In Chapter 3, I asked how simulations could be used to inform important design choices used in selection experiments. Specifically, I focused on the effects of both within- and between-line variation on estimated power, when detecting small, medium and large effect sizes. Using mixed-effect models on simulated data, I demonstrated that commonly used designs with realistic levels of variation could be underpowered for substantial effect sizes. Thus, use of simulation-based power analysis provides an effective way to avoid under or overpowering a study designs incorporating variation due to random effects. In Chapter 4, I 3 investigated how Ivermectin dosage and changes in population density affect the rate of resistance evolution. I exposed replicate lines of C. remanei to two doses of Ivermectin (high and low) to assess relative survival of lines selected in drug-treated environments compared to untreated controls over 10 generations. Additionally, I maintained lines where mortality was imposed randomly to control for differences in density between drug treatments and to distinguish between the evolutionary consequences of drug treatment versus ecological processes affected by changes in density-dependent feedback. Intriguingly, both drug-selected and random-mortality lines showed an increase in survivorship when challenged with Ivermectin; the magnitude of this increase varied with the intensity of selection and life-history stage. The results suggest that interactions between density-dependent processes and life history may mediate evolved changes in susceptibility to control measures, which could result in misleading conclusions about the evolution of heritable resistance following drug treatment. In Chapter 5, I investigated whether the apparent changes in drug susceptibility found in Chapter 4 were related to evolved changes in life-history of C. remanei populations after selection in drug-treated and random-mortality environments. Rapid passage of lines in the drug-free environment had no effect on the measured life-history traits. In the drug-free environment, adult size and fecundity of drug-selected lines increased compared to the controls but drug selection did not affect lifespan. In the treated environment, drug-selected lines showed increased lifespan and fecundity relative to controls. Adult size of randomly culled lines responded in a similar way to drug-selected lines in the drug-free environment, but no change in fecundity or lifespan was observed in either environment. The results suggest that life histories of nematodes can respond to selection as a result of the application of control measures. Failure to take these responses into account when applying control measures could result in adverse outcomes, such as larger and more fecund parasites, as well as over-estimation of the development of genetically controlled resistance. In conclusion, my thesis shows that there may be a complex relationship between drug selection, density-dependent regulatory processes and life history of populations challenged with control measures. This relationship could have implications for how resistance is monitored and managed if life histories of parasitic species show such eco-evolutionary responses to drug application.

Outcome of childhood malignancies at the University of Port Harcourt Teaching Hospital: a call for implementation of palliative care.

Background: Cancers in children are yet to be recognised as an important cause of childhood morbidity and mortality in developing countries where more than 70% of the world annual cases occur. Despite the limited resources and whatever the projected outcome, children with cancer need treatment, be it curative or palliative. Objectives: To determine outcome of cancers in children at the UPTH; identify factors that influence outcome, highlight the need for palliative care. Method: A retrospective study of cases of childhood malignancies admitted into Paediatric Oncology unit of UPTH over a two year period. Clinical profile of patients and outcome were analyzed using SPSS version 20.0. Results: Sixty cases were analysed: 35(58.3%) males, 25(41.7%) females giving a M:F ratio of 1.4:1. Under-fives constituted 55%. Twenty-seven (45%) patients presented within 4 weeks of onset of symptoms. Median duration of symptoms before presentation was 8 weeks while 36 (60%) had metastatic disease at diagnosis. Twenty patients (33.3%) defaulted with or without specific treatment. Mortality was recorded in 26(43.4%) of cases. Conclusion: There were more cases of cancer amongst under-fives with male preponderance. Late presentation, financial constraints and high default rate were contributory factors to poor outcome in most cases. Lack of palliative care left many families to face their sufferings.

Using interaction data for improving the offline and online evaluation of search engines

This thesis investigates how web search evaluation can be improved using historical interaction data. Modern search engines combine offline and online evaluation approaches in a sequence of steps that a tested change needs to pass through to be accepted as an improvement and subsequently deployed. We refer to such a sequence of steps as an evaluation pipeline. In this thesis, we consider the evaluation pipeline to contain three sequential steps: an offline evaluation step, an online evaluation scheduling step, and an online evaluation step. In this thesis we show that historical user interaction data can aid in improving the accuracy or efficiency of each of the steps of the web search evaluation pipeline. As a result of these improvements, the overall efficiency of the entire evaluation pipeline is increased. Firstly, we investigate how user interaction data can be used to build accurate offline evaluation methods for query auto-completion mechanisms. We propose a family of offline evaluation metrics for query auto-completion that represents the effort the user has to spend in order to submit their query. The parameters of our proposed metrics are trained against a set of user interactions recorded in the search engine’s query logs. From our experimental study, we observe that our proposed metrics are significantly more correlated with an online user satisfaction indicator than the metrics proposed in the existing literature. Hence, fewer changes will pass the offline evaluation step to be rejected after the online evaluation step. As a result, this would allow us to achieve a higher efficiency of the entire evaluation pipeline. Secondly, we state the problem of the optimised scheduling of online experiments. We tackle this problem by considering a greedy scheduler that prioritises the evaluation queue according to the predicted likelihood of success of a particular experiment. This predictor is trained on a set of online experiments, and uses a diverse set of features to represent an online experiment. Our study demonstrates that a higher number of successful experiments per unit of time can be achieved by deploying such a scheduler on the second step of the evaluation pipeline. Consequently, we argue that the efficiency of the evaluation pipeline can be increased. Next, to improve the efficiency of the online evaluation step, we propose the Generalised Team Draft interleaving framework. Generalised Team Draft considers both the interleaving policy (how often a particular combination of results is shown) and click scoring (how important each click is) as parameters in a data-driven optimisation of the interleaving sensitivity. Further, Generalised Team Draft is applicable beyond domains with a list-based representation of results, i.e. in domains with a grid-based representation, such as image search. Our study using datasets of interleaving experiments performed both in document and image search domains demonstrates that Generalised Team Draft achieves the highest sensitivity. A higher sensitivity indicates that the interleaving experiments can be deployed for a shorter period of time or use a smaller sample of users. Importantly, Generalised Team Draft optimises the interleaving parameters w.r.t. historical interaction data recorded in the interleaving experiments. Finally, we propose to apply the sequential testing methods to reduce the mean deployment time for the interleaving experiments. We adapt two sequential tests for the interleaving experimentation. We demonstrate that one can achieve a significant decrease in experiment duration by using such sequential testing methods. The highest efficiency is achieved by the sequential tests that adjust their stopping thresholds using historical interaction data recorded in diagnostic experiments. Our further experimental study demonstrates that cumulative gains in the online experimentation efficiency can be achieved by combining the interleaving sensitivity optimisation approaches, including Generalised Team Draft, and the sequential testing approaches. Overall, the central contributions of this thesis are the proposed approaches to improve the accuracy or efficiency of the steps of the evaluation pipeline: the offline evaluation frameworks for the query auto-completion, an approach for the optimised scheduling of online experiments, a general framework for the efficient online interleaving evaluation, and a sequential testing approach for the online search evaluation. The experiments in this thesis are based on massive real-life datasets obtained from Yandex, a leading commercial search engine. These experiments demonstrate the potential of the proposed approaches to improve the efficiency of the evaluation pipeline.

Chromatographic determination of fatty acids profiles in regionally-produced Portuguese goat cheese along curing

The biochemistry of cheese ripening involves mechanisms such as glycolysis, proteolysis and lipolysis. Fatty acids are released by the action of lipases from different sources, milk, rennet, bacteria, moulds included as secondary starters, and other exogenous lipases, during lipolysis [1]. The composition of the lipid fraction contributes positively to the flavour of cheese, for being precursors of more complex aroma compounds responsible for the characteristic “goaty flavour” of goat cheeses [2]. Goat milk is recognized by its easier digestibility, alkalinity, buffering capacity and certain therapeutic values in medicine and human nutrition [3]. A high total content of fatty acids is strongly linked to a rancid and tart off flavour in goat milk and may be considered undesirable in most cheese varieties [4]. In this sense, the purpose of the present study was to examine the composition and changes in fatty acids and saponification value of goat cheese during curing period (2, 7 and 12 months). Goat cheese was made in industrial unit of Cachão - Mirandela (Trás-os- Montes) with raw milk Serrana goats’ race, salt and rennet from animal origin. During the first two months, the samples were stored in a ripening chamber (9.5-11 °C and RH 75-85%). From the second month to one year, the samples were stored in a preservation chamber (10.5-12 °C and RH 75-85%). The fatty acids profile of the inner part of the cheese was analyzed by gas-chromatography coupled to flame ionization detection (GC-FID). The degree of saponification was determined both in the crust and inside the cheese by HCl titration of ethanol KOH solution of the samples. Twenty-six fatty acids (FA) were identified and quantified in the inner part of the cheese (total fat was 45-46 g/100 g during the curing period). Saturated fatty acids (SFA) did not change up to 7 months of curing, increasing only after 12 months, being palmitic (C16:0), stearic (C18:0), myristic (C14:0) and capric (C10:0) acids the most abundant FA in this class. Monounsaturated fatty acids (MUFA) decreased only after 12 months, and oleic acid (C18:1) was the predominant FA. In polyunsaturated fatty acids (PUFA) class, the most abundant were linoleic (C18:2) and linolenic (C18:3) acids, and followed the same tendency of MUFA. This is corroborated by an increase in the degree of saponification, either in the crust as in the inner part of the cheese, after 12 months of curing, probably related with the saturation of the fatty acids [3]. Extra-long curing can be done in cheeses produced with goat milk up to seven months of storage without changing the total fat and individual FA content.

Five years retrospective cohort analysis of treatment outcomes of TB-HIV patients at a PEPFAR/DOTS Centre in South Eastern Nigeria.

Background: Human immunodeficiency virus (HIV) associated tuberculosis (TB) remains a major global public health challenge, with an estimated 1.4 million patients worldwide. Co-infection with HIV leads to challenges in the diagnosis and treatment of patients. Objectives: The aim of this study was to assess treatment outcomes of a cohort of smear positive TB-HIV co-infected patients over a five-year study period. Methods: A retrospective cohort study of 600 smear-positive tuberculosis patients registered at the chest unit of the University of Nigeria Teaching Hospital, Enugu from January 2008 to December 2012 was done. The data was analyzed using SPSS Version 17. Results: One hundred and three (17.2%) of the patients were co-infected with TB/HIV, while 398 (66.3%) and 99 (16.5%) were HIV negative and unknown respectively. Among the co-infected patients, 45(43.7%) were cured as against 222(55.8%) in the TBHIV negatives (Z=4.53, p=0.000, 95%CI= 0.12-0.34). Respectively in the TB-HIV co-infected and TB-HIV negative patients, treatment completed were 21(20.4%) and 71(17.8%) (Z=9.15, p=0.000, 95%= 0.4035-0.60); defaulted 19(18.5%) vs 70 (17.6%) (Z=9.29, p=0.000, 95%CI=0.42-0.60), died 10(9.7%) vs. 6(1.5%) (Z=1.22, p=0.224, 95%CI= -0.0286-0.1086), and failures were 1(0.9%) vs. 7(1.8%) (Z=2.48, p=0.013, 95%CI=0.04-0.10). Treatment success rate was lower in TB-HIV co-infected patients, 64.1% compared to TB-HIV negative patients with 73.6%. Also those that defaulted among the TB-HIV co-infected patients (18.5%) were higher than 17.6% among TB-HIV negative patients, a difference of 0.9%. Conclusion: Findings demonstrate that HIV co-infection affects TB treatment outcomes adversely. Treatment adherence, timely and sustained access to antiretroviral therapy for TB/HIV co-infected patients are important.

Interorganizational Innovation: The Role of Suppliers in Enhancing Buyer Innovation

This dissertation explores the effect of innovative knowledge transfer across supply chain partners. My research seeks to understand the manner by which a firm is able to benefit from the innovative capabilities of its supply chain partners and utilize the external knowledge they hold to increase its own levels of innovation. Specifically, I make use of patent data as a proxy for firm-level innovation and develop both independent and dependent variables from the data contained within the patent filings. I further examine the means by which key dyadic and portfolio supply chain relationship characteristics moderate the relationship between supplier innovation and buyer innovation. I investigate factors such as the degree of transactional reciprocity between the buyer and supplier, the similarity of the firms’ knowledge bases, and specific chain characteristics (e.g., geographic propinquity) to provide greater understanding of the means by which the transfer of innovative knowledge across firms in a supply chain can be enhanced or inhibited. This dissertation spans three essays to provide insights into the role that supply chain relationships play in affecting a focal firm’s level of innovation. While innovation has been at the core of a wide body of research, very little empirical work exists that considers the role of vertical buyer-supplier relationships on a firm’s ability to develop new and novel innovations. I begin by considering the fundamental unit of analysis within a supply chain, the buyer-supplier dyad. After developing initial insights based on the interactions between singular buyers and suppliers, essay two extends the analysis to consider the full spectrum of a buyer’s supply base by aggregating the individual buyer-supplier dyad level data into firm-supply network level data. Through this broader level of analysis, I am able to examine how the relational characteristics between a buyer firm and its supply base affect its ability to leverage the full portfolio of its suppliers’ innovative knowledge. Finally, in essay three I further extend the analysis to explore the means by which a buyer firm can use its suppliers to enhance its ability to access distant knowledge held by other organizations that the buyer is only connected to indirectly through its suppliers.

Outcome Prediction of Consciousness Disorders in the Acute Stage Based on a Complementary Motor Behavioural Tool.

INTRODUCTION: Attaining an accurate diagnosis in the acute phase for severely brain-damaged patients presenting Disorders of Consciousness (DOC) is crucial for prognostic validity; such a diagnosis determines further medical management, in terms of therapeutic choices and end-of-life decisions. However, DOC evaluation based on validated scales, such as the Revised Coma Recovery Scale (CRS-R), can lead to an underestimation of consciousness and to frequent misdiagnoses particularly in cases of cognitive motor dissociation due to other aetiologies. The purpose of this study is to determine the clinical signs that lead to a more accurate consciousness assessment allowing more reliable outcome prediction. METHODS: From the Unit of Acute Neurorehabilitation (University Hospital, Lausanne, Switzerland) between 2011 and 2014, we enrolled 33 DOC patients with a DOC diagnosis according to the CRS-R that had been established within 28 days of brain damage. The first CRS-R assessment established the initial diagnosis of Unresponsive Wakefulness Syndrome (UWS) in 20 patients and a Minimally Consciousness State (MCS) in the remaining13 patients. We clinically evaluated the patients over time using the CRS-R scale and concurrently from the beginning with complementary clinical items of a new observational Motor Behaviour Tool (MBT). Primary endpoint was outcome at unit discharge distinguishing two main classes of patients (DOC patients having emerged from DOC and those remaining in DOC) and 6 subclasses detailing the outcome of UWS and MCS patients, respectively. Based on CRS-R and MBT scores assessed separately and jointly, statistical testing was performed in the acute phase using a non-parametric Mann-Whitney U test; longitudinal CRS-R data were modelled with a Generalized Linear Model. RESULTS: Fifty-five per cent of the UWS patients and 77% of the MCS patients had emerged from DOC. First, statistical prediction of the first CRS-R scores did not permit outcome differentiation between classes; longitudinal regression modelling of the CRS-R data identified distinct outcome evolution, but not earlier than 19 days. Second, the MBT yielded a significant outcome predictability in the acute phase (p<0.02, sensitivity>0.81). Third, a statistical comparison of the CRS-R subscales weighted by MBT became significantly predictive for DOC outcome (p<0.02). DISCUSSION: The association of MBT and CRS-R scoring improves significantly the evaluation of consciousness and the predictability of outcome in the acute phase. Subtle motor behaviour assessment provides accurate insight into the amount and the content of consciousness even in the case of cognitive motor dissociation.

A Phylogenetic Classification of the Video-Game Industry’s Business Model Ecosystem

Part 8: Business Strategies Alignment

Forecasting errors, directional accuracy and profitability of currency trading: The case of EUR/USD exchange rate

We provide a comprehensive study of out-of-sample forecasts for the EUR/USD exchange rate based on multivariate macroeconomic models and forecast combinations. We use profit maximization measures based on directional accuracy and trading strategies in addition to standard loss minimization measures. When comparing predictive accuracy and profit measures, data snooping bias free tests are used. The results indicate that forecast combinations, in particular those based on principal components of forecasts, help to improve over benchmark trading strategies, although the excess return per unit of deviation is limited.

Application of Lidocaine Spray for Tracheal Intubation in Neonates - A Clinical Trial Study

Background: Tracheal intubation is extremely distressing, painful, and may influence heart rate and blood pressure. Sedatives, analgesics, and muscle relaxants are not commonly used for intubation in neonates. Objectives: This study aimed to evaluate the effects of lidocaine spray as a non-intravenous drug before neonatal intubation on blood pressure, heart rate, oxygen saturation and time of intubation. Patients and Methods: In a randomized, controlled study each neonate was randomly assigned to one of the two study groups by staffs who were not involved in the infant's care. The allocation concealment was kept in an opaque sealed envelope, and the investigators, the patient care team, and the assessors were blinded to the treatment allocation. The selected setting was NICU unit of a teaching hospital in Ilam city, Iran and participants were 60 neonates with indication of tracheal intubation with gestational age >30 weeks. Patients in the treatment group received lidocaine spray and the placebo group received spray of normal saline prior to intubation. Main outcome measurements were the mean rates of blood pressure, heart rate, oxygen saturation, intubation time and lidocaine side effects were measured before and after intubation. Results: Totally 60 newborns including 31 boys and 29 girls were entered into the study (drug group n = 30; placebo group n = 30). Boy/girl ratio in treatment and placebo groups were 1.3 and 0.88, respectively. Mean age ± SD of participants was 34.1 ± 24.8 hours (treatment: 35.3 ± 25.7; placebo: 32.9 ± 24.3; P < 0.0001). Mean weight ± SD of neonates was 2012.5 ± 969 g. Application of lidocaine spray caused a significant reduction of mean intubation time among treatment group compared with placebo group (treatment: 15.03 ± 2.2 seconds; placebo: 18.3 ± 2.3 seconds; P < 0.0001). Mean blood pressure, heart rate and oxygen saturation rate, among neonates in treatment group was reduced after intubation compared with their relevant figures before intubation; however, their differences were not statistically significant except for mean oxygen saturation rate that was reduced significantly in placebo group. No side effects were observed during study. Conclusions: Though the current study revealed some promising results in the application of lidocaine spray during neonatal intubation without any considerable side effects; however, the current investigation could only be considered as a pilot study for further attempts in different locations with higher sample sizes and in different situations.

In two waters: contemporary evolution of lagoonal and marine white seabream (Diplodus sargus) populations

Brackish water ecosystems are often exposed to wide variations in environmental variables, including temperature and salinity, which may cause strong selective pressures on organisms modifying the genetic patterns of species. The aim of this work was to test whether there is a ‘divergence-with-gene flow’ in coastal lagoon populations of white seabream (Diplodus sargus) (Ria Formosa, S Portugal and Mar Menor, SE Spain) respect to four marine populations, by using partial sequences of cyt b mitochondrial gene and information from nine microsatellite loci. Genetic diversity was highest in both coastal lagoons (Mar Menor and Ria Formosa) considering mitochondrial and nuclear markers. Although some of FST population pairwise comparisons were not significant, analyses of molecular variance (AMOVAs) detected differences between groups (coastal lagoon and marine) close to significance. Also, only two haplotypes (Cytb-17 and Cytb-18) were detected in both coastal lagoon sampling sites and these localities (Mar Menor and Ria Formosa) showed the highest number of singletons, some of them with a high number of mutations, as has been already described for other Mar Menor populations (Pomatochistus marmoratus and Holothuria polii). Also, several tests detected significant positive and balancing selection considering mtDNA and microsatellite data. These data support the hypothesis of selection as one of the drivers of the genetic differences found between coastal lagoon and marine populations. The life strategy adopted by Diplodus sargus in coastal lagoons allows it to decrease its mortality rate and improve the heritability of its genes. Also, the increase time spent in coastal lagoons with different temperatures and salinities favours the fitness selection and the maintenance of exclusive haplotypes and genotypes in coastal lagoon inhabitants favouring the ‘divergence-with-gene-flow’.