Hemorrhagic cystitis following allogeneic hematopoietic stem cell transplantation: experience in a pediatric oncological institution

OBJECTIVE

To analyze the risk factors associated with hemorrhagic cystitis (HC) severity and the treatment strategies available in HC patients following allogeneic hematopoietic stem cell transplantation (AHSCT).

MATERIALS AND METHODS

A retrospective study of medical records was carried out. Patients with HC following AHSCT treated from 2017 to 2021 were divided into two groups according to severity -mild and severe. Demographic data, disease-specific characteristics, urological sequelae, and overall mortality were compared between both groups. The hospital's protocol was used for patient management.

RESULTS

33 episodes of HC were collected in 27 patients, 72.7% of whom were male. HC incidence following AHSCT was 23.4% (33/141). 51.5% of HCs were severe (grades III-IV). Severe graft host disease (GHD) (grades III-IV) and thrombopenia at HC onset were associated with severe HC (p= 0.043 and p= 0.039, respectively). This group had longer hematuria times (p< 0.001) and required more platelet transfusions (p= 0.003). In addition, 70.6% required bladder catheterization, but only 1 case needed percutaneous cystostomy. None of the patients with mild HC required catheterization. No differences were found in terms of urological sequelae or overall mortality.

CONCLUSIONS

Severe HC could be predicted thanks to the presence of severe GHD or thrombopenia at HC onset. Severe HC can be managed with bladder catheterization in most of these patients. A standardized protocol may help reduce the need for invasive procedures in patients with mild HC.

Presence of microplastics in water, sediments and fish species in an urban coastal environment of Fiji, a Pacific small island developing state

Microplastics (MP) in the marine environment are widely reported. However, MP occurrence in some geographical areas such as from Small Island Developing States (SIDS) is missing. The main aim of this study was to assess MP levels in the urban coastal environment of Suva, the capital of the Republic of Fiji. Microplastics were measured from surface water, sediments and fish gastrointestinal tracts (GI) from three sites adjacent to Suva. In addition, an evaluation on the contribution from the local sewage treatment plant to MP levels was undertaken. In general, low levels of MP in water and sediments were detected, but significant differences were observed among sites. The sewage treatment plant was shown to contribute to MP levels in sediment but not in water. Species ingestion of MP was high and associated with MP in sediments. Fibres and fragments were the predominant type of MP, and fifteen different polymers were detected, with higher percentages of polyethylene, latex and polypropylene. In conclusion, MP were found in Suva coastal environment and these MP were associated to land based human activities.

P5477Usefulness of hypocalcemia at admission as a prognostic marker in patients with acute coronary syndromes

Background

Few studies have focused on the role of serum calcium levels (SCa) in patients with acute myocardial infarction (AMI).

Purpose

This study aimed to analyze the value of SCa as a prognostic marker in patients with AMI, including both with or without ST elevation.

Methods

From January-2015 to December-2017, all consecutive patients with AMI admitted to a tertiary care hospital were included. For the purpose of this study, total SCa levels were recorded at admission in each patient. Blood samples were obtained at the first medical contact when the patient arrived to the hospital. Patients were classified according to quartiles depending on their SCa at admission: Q1, under 8.3 mg/dl (N=300); Q2, between 8.4–8.7 mg/dl (N=264); Q3, between 8.8–9.1 mg/dl (N=279) and Q4, over 9.1 mg/dl (N=283).

Results

A total cohort of 1126 patients was included, 679 (60.3%) had STEMI and 447 (39.7%) were NSTEMI patients. Patients in the Q1 had more in-hospital complications, such as heart failure, bleeding events, new onset AMI, atrioventricular block and contrast induced nephropathy. Patients in the Q1 had higher in-hospital and one-year mortality as compared to that of patients in the Q2-Q4. After multivariate adjustment (Table), low SCa (<8.3mg/dl) remained as an independent predictor of in-hospital mortality (OR 2.91, 95% CI (1.15–7.41), p=0.025). These results were consistent in STEMI and NSTEMI patients.

Multivariable analysis Variable OR (95% CI) p GRACE score 1.00 (0.99–1.02) 0.727 CRUSADE score 1.03 (1.01–1.06) 0.011 Age (per year) 1.05 (1.00–1.09) 0.034 STEMI 1.35 (0.41–4.46) 0.617 Diabetes 2.57 (0.97–6.79) 0.056 Low SCa (<8.3) 2.91 (1.15–7.41) 0.025 Killip class at admission   1 Reference   2 4.73 (1.31–17.1) 0.018   3 6.83 (1.70–27.5) 0.007   4 9.83 (1.44–67.1) 0.020 STEMI: ST segment elevation myocardial infarction; SCa: Serum calcium levels; OR: Odds ratio; CI: Confidence interval.

Conclusion

In patients with AMI, low SCa levels at admission (<8.3mg/dl) are independently associated with higher mortality.

Indications of strong adaptive population genetic structure in albacore tuna (Thunnus alalunga) in the southwest and central Pacific Ocean

Albacore tuna (Thunnus alalunga) has a distinctly complex life history in which juveniles and adults separate geographically but at times inhabit the same spaces sequentially. The species also migrates long distances and presumably experiences varied regimes of physical stress over a lifetime. There are, therefore, many opportunities for population structure to arise based on stochastic differences or environmental factors that promote local adaptation. However, with the extent of mobility consistently demonstrated by tagged individuals, there is also a strong argument for panmixia within an ocean basin. It is important to confirm such assumptions from a population genetics standpoint for this species in particular because albacore is one of the principal market tuna species that sustains massive global fisheries and yet is also a slow-growing temperate tuna. Consequently, we used 1,837 neutral SNP loci and 89 loci under potential selection to analyze population genetic structure among five sample groups collected from the western and central South Pacific. We found no evidence to challenge panmixia at neutral loci, but strong indications of structuring at adaptive loci. One population sample, from French Polynesia in 2004, was particularly differentiated. Unfortunately, the current study cannot infer whether the divergence is geographic or temporal, or possibly caused by sample distribution. We encourage future studies to include potentially adaptive loci and to continue fine-scale observations within an ocean basin, and not to assume genome-wide panmixia.

Essential waters: Young bull sharks in Fiji's largest riverine system

Coastal and estuarine systems provide critical shark habitats due to their relatively high productivity and shallow, protected waters. The young (neonates, young-of-the-year, and juveniles) of many coastal shark species occupy a diverse range of habitats and areas where they experience environmental variability, including acute and seasonal shifts in local salinities and temperatures. Although the location and functioning of essential shark habitats has been a focus in recent shark research, there is a paucity of data from the South Pacific. In this study, we document the temporal and spatial distribution, age class composition, and environmental parameters of young bull sharks (Carcharhinus leucas) in the Rewa, Sigatoka, and Navua Rivers, Fiji's three largest riverine systems. One hundred and seventy-two young bull sharks were captured in fisheries-independent surveys from January 2016 to April 2018. The vast majority of the captures were neonates. Seasonality in patterns of occurrence of neonate individuals suggests a defined parturition period during summer. Environmental parameters between the Rewa and the Sigatoka River differed significantly, as did the recorded young bull sharks abundance. According to the surveys, young bull sharks occur in all three rivers with the Rewa River likely representing essential habitat for newly born bull sharks. These results enhance the understanding of bull shark ecology in Fiji and provide a scientific basis for the implementation of local conservation strategies that contribute to the protection of critical habitats.

The effects of a stressed inshore urban reef on coral recruitment in Suva Harbour, Fiji

A relic inshore reef ecosystem adjacent to the Fijian capital of Suva and another remote inshore reef were monitored monthly from July 2014 to July 2015 for coral recruitment, sedimentation rates, coral cover, temperature, and light intensity. Despite a major sewage spill in Suva Harbour in December 2014, the municipal inshore site exposed to constant anthropogenic activity, recorded no significant differences in coral spat abundance (except for the family Poritidae) on artificial substrata compared to the remote inshore site. Total yearly spat abundance was 106 on municipal reef and 132 on remote reef, while average daily sediment trap collection rates (g cm2/day) were significantly higher in the municipal site for the entire duration of monitoring. Total annual particulate organic matter content in sediment was also significantly higher in the municipal site (107.51 g cm2), compared to the remote site (43.37 g cm2). Mean light intensity was significantly lower for the municipal site (69.81 lum/ft2) compared to the remote site (239.26 lum/ft2), with Photosynthetically Active Radiation also lower for the former (800-1,066.66 µmol m-2 s-1) compared to the latter (3,266.66-3,600 µmol m-2 s-1). The lack of significant differences in coral spat recruitment rates suggests that settling larvae may be unable to distinguish between sub-optimal and optimal sites probably as a consequence of interference with coral settlement cues arising from anthropogenic development.

The population genomics of yellowfin tuna (Thunnus albacares) at global geographic scale challenges current stock delineation

Yellowfin tuna, Thunnus albacares, is one of the most important seafood commodities in the world. Despite its great biological and economic importance, conflicting evidence arises from classical genetic and tagging studies concerning the yellowfin tuna population structure at local and global oceanic scales. Access to more powerful and cost effective genetic tools would represent the first step towards resolving the population structure of yellowfin tuna across its distribution range. Using a panel of 939 neutral Single Nucleotide Polymorphisms (SNPs), and the most comprehensive data set of yellowfin samples available so far, we found genetic differentiation among the Atlantic, Indian and Pacific oceans. The genetic stock structure analysis carried out with 33 outlier SNPs, putatively under selection, identified discrete populations within the Pacific Ocean and, for the first time, also within the Atlantic Ocean. Stock assessment approaches that consider genetic differences at neutral and adaptive genomic loci should be routinely implemented to check the status of the yellowfin tuna, prevent illegal trade, and develop more sustainable management measures.

Discovery of a multispecies shark aggregation and parturition area in the Ba Estuary, Fiji Islands

Population declines in shark species have been reported on local and global scales, with overfishing, habitat destruction and climate change posing severe threats. The lack of species-specific baseline data on ecology and distribution of many sharks, however, makes conservation measures challenging. Here, we present a fisheries-independent shark survey from the Fiji Islands, where scientific knowledge on locally occurring elasmobranchs is largely still lacking despite the location's role as a shark hotspot in the Pacific. Juvenile shark abundance in the fishing grounds of the Ba Estuary (north-western Viti Levu) was assessed with a gillnet- and longline-based survey from December 2015 to April 2016. A total of 103 juvenile sharks identified as blacktip Carcharhinus limbatus (n = 57), scalloped hammerhead Sphyrna lewini (n = 35), and great hammerhead Sphyrna mokarran (n = 11) sharks were captured, tagged, and released. The condition of umbilical scars (68% open or semihealed), mean sizes of individuals (±SD) (C. limbatus: 66.5 ± 3.8 cm, S. lewini: 51.8 ± 4.8 cm, S. mokarran 77.4 ± 2.8 cm), and the presence of these species over recent years (based on fishermen interviews), suggest that the Ba Estuary area is a critical habitat for multiple species that are classified as "Near Threatened" or "Endangered." Specifically, the area likely acts as a parturition ground over the studied period, and potentially as a subsequent nursery area. We identified subareas of high abundance and found that temperature, salinity and depth acted as small-scale environmental drivers of shark abundance. The data suggests a tendency for species-specific spatial use, both horizontally (i.e., between sampling areas) and vertically (i.e., across the water column). These results enhance the understanding of shark ecology in Fiji and provide a scientific basis for the implementation of local conservation strategies that contribute to the protection of these threatened species.

In vitro efficacy of a first-generation valosin-containing protein inhibitor (CB-5083) against canine lymphoma

Valosin-containing protein (VCP), through its critical role in the maintenance of protein homeostasis, is a promising target for the treatment of several malignancies, including canine lymphoma. CB-5083, a first-in-class VCP inhibitor, exerts cytotoxicity through the induction of irreversible proteotoxic stress and possesses a broad spectrum of anticancer activity. Here, we determined the cytotoxicity CB-5083 in canine lymphoma cells and its mechanism of action in vitro. Canine lymphoma cell lines were treated with varying concentrations of CB-5083 and assessed for viability by trypan blue exclusion and apoptosis by caspase activity assays. The mechanism of CB-5083 action was determined by immunoblotting and RT-qPCR analyses of Lys48 ubiquitination and markers of ER stress (DDIT3), autophagy (SQSTM1, MAP1LC3A) and DNA damage (γH2AX). Unfolded protein response markers were also evaluated by immunoblotting (eIF2α, P-eIF2α) and RT-qPCR (ATF4). CB-5083 treatment resulted in preferential cytotoxicity in canine lymphoma cell lines over control peripheral blood mononuclear cells. CB-5083 rapidly disrupted the ubiquitin-dependent protein degradation system, inducing sustained ER stress as indicated by a dramatic increase in DDIT3. Activation of the unfolded protein response occurred through the increase eIF2α phosphorylation and increased transcription of ATF4, but did not re-establish protein homeostasis. Cells rapidly underwent apoptosis through activation of the caspase cascade. These results further validate VCP as an attractive target for the treatment of canine lymphoma and identify CB-5083 as a novel therapy with clinical potential for this malignancy.

Update in Infectious Diseases 2017

Antimicrobial resistance in complex models of continuous infection is a current issue. The update 2017 course addresses about microbiological, epidemiological and clinical aspects useful for a current approach to infectious disease. During the last year, nosocomial pneumonia approach guides, recommendations for management of yeast and filamentous fungal infections, review papers on the empirical approach to peritonitis and extensive guidelines on stewardship have been published. HIV infection is being treated before and more intensively. The implementation of molecular biology, spectrometry and inmunology to traditional techniques of staining and culture achieve a better and faster microbiological diagnosis. Finally, the infection is increasingly integrated, assessing non-antibiotic aspects in the treatment.

Sex Chromosome Evolution, Heterochiasmy, and Physiological QTL in the Salmonid Brook Charr Salvelinus fontinalis

Whole-genome duplication (WGD) can have large impacts on genome evolution, and much remains unknown about these impacts. This includes the mechanisms of coping with a duplicated sex determination system and whether this has an impact on increasing the diversity of sex determination mechanisms. Other impacts include sexual conflict, where alleles having different optimums in each sex can result in sequestration of genes into nonrecombining sex chromosomes. Sex chromosome development itself may involve sex-specific recombination rate (i.e., heterochiasmy), which is also poorly understood. The family Salmonidae is a model system for these phenomena, having undergone autotetraploidization and subsequent rediploidization in most of the genome at the base of the lineage. The salmonid master sex determining gene is known, and many species have nonhomologous sex chromosomes, putatively due to transposition of this gene. In this study, we identify the sex chromosome of Brook Charr Salvelinus fontinalis and compare sex chromosome identities across the lineage (eight species and four genera). Although nonhomology is frequent, homologous sex chromosomes and other consistencies are present in distantly related species, indicating probable convergence on specific sex and neo-sex chromosomes. We also characterize strong heterochiasmy with 2.7-fold more crossovers in maternal than paternal haplotypes with paternal crossovers biased to chromosome ends. When considering only rediploidized chromosomes, the overall heterochiasmy trend remains, although with only 1.9-fold more recombination in the female than the male. Y chromosome crossovers are restricted to a single end of the chromosome, and this chromosome contains a large interspecific inversion, although its status between males and females remains unknown. Finally, we identify quantitative trait loci (QTL) for 21 unique growth, reproductive, and stress-related phenotypes to improve knowledge of the genetic architecture of these traits important to aquaculture and evolution.

Null alleles are ubiquitous at microsatellite loci in the Wedge Clam (Donax trunculus)

Recent studies have reported an unusually high frequency of nonamplifying alleles at microsatellite loci in bivalves. Null alleles have been associated with heterozygous deficits in many studies. While several studies have tested for its presence using different analytical tools, few have empirically tested for its consequences in estimating population structure and differentiation. We characterised 16 newly developed microsatellite loci and show that null alleles are ubiquitous in the wedge clam, Donax trunculus. We carried out several tests to demonstrate that the large heterozygous deficits observed in the newly characterised loci were most likely due to null alleles. We tested the robustness of microsatellite genotyping for population assignment by showing that well-recognised biogeographic regions of the south Atlantic and south Mediterranean coast of Spain harbour genetically different populations.

Combining next-generation sequencing and online databases for microsatellite development in non-model organisms

Next-generation sequencing (NGS) is revolutionising marker development and the rapidly increasing amount of transcriptomes published across a wide variety of taxa is providing valuable sequence databases for the identification of genetic markers without the need to generate new sequences. Microsatellites are still the most important source of polymorphic markers in ecology and evolution. Motivated by our long-term interest in the adaptive radiation of a non-model species complex of whitefishes (Coregonus spp.), in this study, we focus on microsatellite characterisation and multiplex optimisation using transcriptome sequences generated by Illumina® and Roche-454, as well as online databases of Expressed Sequence Tags (EST) for the study of whitefish evolution and demographic history. We identified and optimised 40 polymorphic loci in multiplex PCR reactions and validated the robustness of our analyses by testing several population genetics and phylogeographic predictions using 494 fish from five lakes and 2 distinct ecotypes.

Genetic diversity at neutral and adaptive loci determines individual fitness in a long-lived territorial bird

There is compelling evidence about the manifest effects of inbreeding depression on individual fitness and populations' risk of extinction. The majority of studies addressing inbreeding depression on wild populations are generally based on indirect measures of inbreeding using neutral markers. However, the study of functional loci, such as genes of the major histocompatibility complex (MHC), is highly recommended. MHC genes constitute an essential component of the immune system of individuals, which is directly related to individual fitness and survival. In this study, we analyse heterozygosity fitness correlations of neutral and adaptive genetic variation (22 microsatellite loci and two loci of the MHC class II, respectively) with the age of recruitment and breeding success of a decimated and geographically isolated population of a long-lived territorial vulture. Our results indicate a negative correlation between neutral genetic diversity and age of recruitment, suggesting that inbreeding may be delaying reproduction. We also found a positive correlation between functional (MHC) genetic diversity and breeding success, together with a specific positive effect of the most frequent pair of cosegregating MHC alleles in the population. Globally, our findings demonstrate that genetic depauperation in small populations has a negative impact on the individual fitness, thus increasing the populations' extinction risk.

Major histocompatibility complex variation in insular populations of the Egyptian vulture: inferences about the roles of genetic drift and selection

Insular populations have attracted the attention of evolutionary biologists because of their morphological and ecological peculiarities with respect to their mainland counterparts. Founder effects and genetic drift are known to distribute neutral genetic variability in these demes. However, elucidating whether these evolutionary forces have also shaped adaptive variation is crucial to evaluate the real impact of reduced genetic variation in small populations. Genes of the major histocompatibility complex (MHC) are classical examples of evolutionarily relevant loci because of their well-known role in pathogen confrontation and clearance. In this study, we aim to disentangle the partial roles of genetic drift and natural selection in the spatial distribution of MHC variation in insular populations. To this end, we integrate the study of neutral (22 microsatellites and one mtDNA locus) and MHC class II variation in one mainland (Iberia) and two insular populations (Fuerteventura and Menorca) of the endangered Egyptian vulture (Neophron percnopterus). Overall, the distribution of the frequencies of individual MHC alleles (n=17 alleles from two class II B loci) does not significantly depart from neutral expectations, which indicates a prominent role for genetic drift over selection. However, our results point towards an interesting co-evolution of gene duplicates that maintains different pairs of divergent alleles in strong linkage disequilibrium on islands. We hypothesize that the co-evolution of genes may counteract the loss of genetic diversity in insular demes, maximize antigen recognition capabilities when gene diversity is reduced, and promote the co-segregation of the most efficient allele combinations to cope with local pathogen communities.

Physical-anaerobic-chemical process for treatment of dairy cattle manure

An overall treatment process for the removal of nitrogen, methane production and obtention of valuable fertilizers from dairy manure has been investigated in laboratory scale. Solid and liquid fractions were separated by flocculation and screening. The solid fraction contained 81.6%, 84.4%, 58.6% and 85.2% of TS, VS, TKN-N and P(T) originally present in manure. Batch anaerobic digestion of this solid fraction at 50°C resulted in methane production of 29.0 L CH(4)/kg. The liquid fraction, free of suspended solids, was satisfactorily treated at 35°C in an upflow anaerobic sludge blanket reactor operating stably at an organic loading rate of 40.8 g COD/(L·d) reaching a methane production of 10.3 L CH(4)/(L·d). Accumulation of volatile fatty acids did not occur. Ammonia nitrogen concentration in the anaerobic effluent fluctuated between 850-1170 mg NH(4)(+)-N/L and was reduced to values less than 100mg NH(4)(+)-N/L by struvite precipitation.

The role of humans in the diversification of a threatened island raptor

BACKGROUND

Anthropogenic habitat modifications have led to the extinction of many species and have favoured the expansion of others. Nonetheless, the possible role of humans as a diversifying force in vertebrate evolution has rarely been considered, especially for species with long generation times. We examine the influence that humans have had on the colonization and phenotypic and genetic differentiation of an insular population of a long-lived raptor species, the Egyptian vulture (Neophron percnopterus).

RESULTS

The morphological comparison between the Canarian Egyptian vultures and the main and closest population in Western Europe (Iberia) indicated that insular vultures are significantly heavier (16%) and larger (about 3%) than those from Iberia. Bayesian and standard genetic analyses also showed differentiation (FST = 0.11, p < 0.01). The inference of changes in the effective size of the Canarian deme, using two likelihood-based Bayesian approaches, suggested that the establishment of this insular population took place some 2500 years ago, matching the date of human colonization. This is consistent with the lack of earlier fossils.

CONCLUSIONS

Archaeological remains show that first colonizers were Berber people from northern Africa who imported goats. This new and abundant food source could have allowed vultures to colonize, expand and adapt to the island environment. Our results suggest that anthropogenic environmental change can induce diversification and that this process may take place on an ecological time scale (less than 200 generations), even in the case of a long-lived species.

Evolutionary origin and phylogeography of the diploid obligate parthenogen Artemia parthenogenetica (Branchiopoda: Anostraca)

BACKGROUND

Understanding the evolutionary origin and the phylogeographic patterns of asexual taxa can shed light on the origin and maintenance of sexual reproduction. We assessed the geographic origin, genetic diversity, and phylogeographic history of obligate parthenogen diploid Artemia parthenogenetica populations, a widespread halophilic crustacean.

METHODOLOGY/PRINCIPAL FINDINGS

We analysed a partial sequence of the Cytochrome c Oxidase Subunit I mitochondrial gene from an extensive set of localities (including Eurasia, Africa, and Australia), and examined their phylogeographic patterns and the phylogenetic relationships of diploid A. parthenogenetica and its closest sexual relatives. Populations displayed an extremely low level of mitochondrial genetic diversity, with one widespread haplotype shared by over 79% of individuals analysed. Phylogenetic and phylogeographic analyses indicated a multiple and recent evolutionary origin of diploid A. parthenogenetica, and strongly suggested that the geographic origin of parthenogenesis in Artemia was in Central Asia. Our results indicate that the maternal sexual ancestors of diploid A. parthenogenetica were an undescribed species from Kazakhstan and A. urmiana.

CONCLUSIONS/SIGNIFICANCE

We found evidence for multiple origin of parthenogenesis in Central Asia. Our results indicated that, shortly after its origin, diploid A. parthenogenetica populations underwent a rapid range expansion from Central Asia towards the Mediterranean region, and probably to the rest of its current geographic distribution. This contrasts with the restricted geographic distribution, strong genetic structure, and regional endemism of sexual Artemia lineages and other passively dispersed sexual continental aquatic invertebrates. We hypothesize that diploid parthenogens might have reached their current distribution in historical times, with a range expansion possibly facilitated by an increased availability of suitable habitat provided by anthropogenic activities, such as the spread of solar saltworks, aided by their natural dispersal vectors (i.e., waterbirds).

Evolution of composition of dairy manure supernatant in a controlled dung pit

Anaerobic conversion of dairy manure into biogas is an attractive way of managing this waste. It is well known that the hydrolysis of large molecules into small, directly biodegradable ones is the rate limiting step of the overall anaerobic process. The present work studies the development of the hydrolytic and acidogenic stages of dairy manure with different solid concentrations (40, 60 and 80 g VS/L) at ambient temperature (20 degrees C). The purpose was to determine the operational conditions that provide a liquid fraction with a high soluble chemical oxygen demand (COD) and a high volatile fatty acids (VFA) content in manure before the methanogenic stage starts up. At 20 degrees C, the evolution of the studied parameters showed that, in a controlled plug-flow dung pit, the hydrolytic and acidogenic stages progressed moderately in a continuous way during the 25 days that the experimentation lasted, whereas no methanization was observed. Supernatant COD and VFA concentrations increased 30% and 107%, respectively, for the 60 g VS/L samples. Manure was also operated at 35 degrees C with a similar increase in supernatant COD but a higher increase in VFA, 154%. For both operational temperatures, the predominant VFAs were, in this order, acetic, propionic and butyric acids. During the operation at 35 degrees C, the methanogenic stage started between days 20 and 25 for the samples with lower solids content, i.e. 40 and 60 g VS/L.

Disentangling vector-borne transmission networks: a universal DNA barcoding method to identify vertebrate hosts from arthropod bloodmeals

Emerging infectious diseases represent a challenge for global economies and public health. About one fourth of the last pandemics have been originated by the spread of vector-borne pathogens. In this sense, the advent of modern molecular techniques has enhanced our capabilities to understand vector-host interactions and disease ecology. However, host identification protocols have poorly profited of international DNA barcoding initiatives and/or have focused exclusively on a limited array of vector species. Therefore, ascertaining the potential afforded by DNA barcoding tools in other vector-host systems of human and veterinary importance would represent a major advance in tracking pathogen life cycles and hosts. Here, we show the applicability of a novel and efficient molecular method for the identification of the vertebrate host's DNA contained in the midgut of blood-feeding arthropods. To this end, we designed a eukaryote-universal forward primer and a vertebrate-specific reverse primer to selectively amplify 758 base pairs (bp) of the vertebrate mitochondrial Cytochrome c Oxidase Subunit I (COI) gene. Our method was validated using both extensive sequence surveys from the public domain and Polymerase Chain Reaction (PCR) experiments carried out over specimens from different Classes of vertebrates (Mammalia, Aves, Reptilia and Amphibia) and invertebrate ectoparasites (Arachnida and Insecta). The analysis of mosquito, culicoid, phlebotomie, sucking bugs, and tick bloodmeals revealed up to 40 vertebrate hosts, including 23 avian, 16 mammalian and one reptilian species. Importantly, the inspection and analysis of direct sequencing electropherograms also assisted the resolving of mixed bloodmeals. We therefore provide a universal and high-throughput diagnostic tool for the study of the ecology of haematophagous invertebrates in relation to their vertebrate hosts. Such information is crucial to support the efficient management of initiatives aimed at reducing epidemiologic risks of arthropod vector-borne pathogens, a priority for public health.

Assortative mating among Lake Malawi cichlid fish populations is not simply predictable from male nuptial colour

Background

Research on the evolution of reproductive isolation in African cichlid fishes has largely focussed on the role of male colours and female mate choice. Here, we tested predictions from the hypothesis that allopatric divergence in male colour is associated with corresponding divergence in preference.

Methods

We studied four populations of the Lake Malawi Pseudotropheus zebra complex. We predicted that more distantly-related populations that independently evolved similar colours would interbreed freely while more closely-related populations with different colours mate assortatively. We used microsatellite genotypes or mesh false-floors to assign paternity. Fisher's exact tests as well as Binomial and Wilcoxon tests were used to detect if mating departed from random expectations.

Results

Surprisingly, laboratory mate choice experiments revealed significant assortative mating not only between population pairs with differently coloured males, but between population pairs with similarly-coloured males too. This suggested that assortative mating could be based on non-visual cues, so we further examined the sensory basis of assortative mating between two populations with different male colour. Conducting trials under monochromatic (orange) light, intended to mask the distinctive male dorsal fin hues (blue v orange) of these populations, did not significantly affect the assortative mating by female P. emmiltos observed under control conditions. By contrast, assortative mating broke down when direct contact between female and male was prevented.

Conclusion

We suggest that non-visual cues, such as olfactory signals, may play an important role in mate choice and behavioural isolation in these and perhaps other African cichlid fish. Future speciation models aimed at explaining African cichlid radiations may therefore consider incorporating such mating cues in mate choice scenarios.

Characterization of polymorphic microsatellite markers in the brine shrimp Artemia (Branchiopoda, Anostraca)

The brine shrimp Artemia is a complex genus containing sexual species and parthenogenetic lineages. Artemia franciscana is native to America and its cysts (diapausing eggs) are used worldwide as a food source in aquaculture. As a consequence, this anostracan has become an invasive species in many hypersaline aquatic ecosystems of other continents. Parthenogenetic Artemia lineages occur only in the Old World. Ten and five microsatellite markers were developed to characterize two populations for A. franciscana and two populations for diploid parthenogenetic Artemia, respectively. For A. franciscana the number of alleles ranged from 11 to 58 per locus, while for parthenogens the number of alleles ranged from three to 10. The levels of heterozygosity in A. franciscana and in parthenogens ranged from 0.115 to 0.976 and from 0.000 to 0.971, respectively. These microsatellite loci showed a high population assignment power, which will be useful for future studies of population genetics and invasive processes in Artemia.

Flocculants effect in biomass retention in a UASB reactor treating dairy manure

The performance and biomass retention of an upflow anaerobic sludge bed (UASB) reactor treating liquid fraction of dairy manure has been investigated at several organic loading rates. Two identical UASB reactors were employed. The biomass of one UASB reactor (FBR) had previously been treated with a cationic polyacrylamide, the other reactor was operated as a control reactor (CR). At 3 and 2 days of HRT both reactors functioned similarly, but at 1.5 days HRT some differences were observed between both effluents. Mean COD(T) removal percentages were 83.4% and 76.5%; COD(VFA) values in effluents were 977 and 2682 mg l(-1) for the FBR and the CR respectively. The VSS initial value in both reactors was 25.66 g VSS, whereas after the experiment the quantities were 31.83 g VSS in the FBR and 23.18 g VSS in the CR reactors. Polymer addition resulted in a higher degree of biomass retention and better performance in the FBR reactor.

Phylogeography and local endemism of the native Mediterranean brine shrimp Artemia salina (Branchiopoda: Anostraca)

There has been a recent appreciation of the ecological impacts of zooplanktonic species invasions. The North American brine shrimp Artemia franciscana is one such alien invader in hyper-saline water ecosystems at a global scale. It has been shown to outcompete native Artemia species, leading to their local extinction. We used partial sequences of the mitochondrial Cytochrome c Oxidase Subunit 1 (COI or cox1) gene to investigate the genetic diversity and phylogeography of A. salina, an extreme halophilic sexual brine shrimp, over its known distribution range (Mediterranean Basin and South Africa) and to assess the extent of local endemism, the degree of population structure and the potential impact of traditional human saltpan management on this species. We also examined the phylogenetic relationships in the genus Artemia using COI sequences. Our results show extensive regional endemism and indicate an early Pleistocene expansion of A. salina in the Mediterranean Basin. Subsequent population isolation in a mosaic of Pleistocene refugia is suggested, with two or three refugia located in the Iberian Peninsula. Two instances of long-distance colonization were also observed. Surprisingly, given its strong phylogeographical structure, A. salina showed a signature of correlation between geographical and genetic distance. Owing to strong 'priority effects', extensive population differentiation is retained, despite dispersal via migrant birds and human management of saltpans. The foreseeable expansion of A. franciscana is likely to be followed by substantial loss of genetic diversity in Mediterranean A. salina. Large genetic divergences between Mediterranean and South African A. salina suggest that the latter deserves species status.

MHC adaptive divergence between closely related and sympatric African cichlids

Background

The haplochromine cichlid species assemblages of Lake Malawi and Victoria represent some of the most important study systems in evolutionary biology. Identifying adaptive divergence between closely-related species can provide important insights into the processes that may have contributed to these spectacular radiations. Here, we studied a pair of sympatric Lake Malawi species, Pseudotropheus fainzilberi and P. emmiltos, whose reproductive isolation depends on olfactory communication. We tested the hypothesis that these species have undergone divergent selection at MHC class II genes, which are known to contribute to olfactory-based mate choice in other taxa.

Methodology/Principal Findings

Divergent selection on functional alleles was inferred from the higher genetic divergence at putative antigen binding sites (ABS) amino acid sequences than at putatively neutrally evolving sites at intron 1, exon 2 synonymous sequences and exon 2 amino acid residues outside the putative ABS. In addition, sympatric populations of these fish species differed significantly in communities of eukaryotic parasites.

Conclusions/Significance

We propose that local host-parasite coevolutionary dynamics may have driven adaptive divergence in MHC alleles, influencing odor-mediated mate choice and leading to reproductive isolation. These results provide the first evidence for a novel mechanism of adaptive speciation and the first evidence of adaptive divergence at the MHC in closely related African cichlid fishes.

Characterisation of solid and liquid fractions of dairy manure with regard to their component distribution and methane production

Dairy manure with a total solids content of 77.2g TS/l was separated by means of screening and coagulation-flocculation treatments, using CaO as coagulant and a cationic polyacrylamide as flocculant, obtaining liquid and solid fractions. The solid fraction separated contained 33.4% of the initial total mass of dairy manure plus chemical solutions, containing also 75.2% of the TS, 80.4% of the VS, 58.5% of the total Kjeldahl nitrogen (TKN) and 87.4% of the total phosphorus (P(T)) present in the initial dairy manure. 83.7% of the liquid fraction chemical oxygen demand (COD) was anaerobically biodegradable (COD(BD)). Methane production for the separated liquid fraction was 0.604l CH4 NCTP/g VS added, being 0.307 and 0.371l CH4 NCTP/g VS added for dairy manure and screened dairy manure, respectively. The characteristics of this liquid fraction would allow its treatment in high loading anaerobic reactors having shorter hydraulic retention times, smaller reactor size and a higher methane volumetric production rate than conventional anaerobic reactors treating either manure or screened manure.

Saving feral horse populations: does it really matter? A case study of wild horses from Doñana National Park in southern Spain

In the 1980s, a conservation programme involving a feral horse population, the Retuertas horses from the Guadalquivir marshes, was started in the Doñana National Park. The analysis of an extensive genetic survey of this population, which now numbers 100 animals, and 10 additional European and North African breeds using DNA polymorphisms from 22 microsatellites is presented. Highly significant fixation indexes were obtained for all pairwise comparisons between the Retuertas population and other breeds. A population neighbour-joining breed phenogram was built using different distance measures, but the Retuertas population failed to cluster with either of the two major clades of European and North African breeds, highlighting its uniqueness. In fact, the Retuertas population was positioned at the base of the trees, which were rooted using donkey samples. Furthermore, assignment tests and the individual Q-matrices obtained with the structure programme isolated the Retuertas breed from the other breeds with only four K groups. Interestingly, some local semi-feral horses, known as Marismeño, also currently living in the Guadalquivir marshes, have some microsatellite genotypes that fall well within the Retuertas cluster. This raises the possibility of incorporating horses from the Marismeño population in a future conservation programme.

The complete mitochondrial genome of the whiting, Merlangius merlangus and the haddock, Melanogrammus aeglefinus: a detailed genomic comparison among closely related species of the Gadidae family

We determined the first complete mitochondrial DNA (mtDNA) sequences for the whiting (Merlangius merlangus, family Gadidae, order Gadiformes) and the haddock (Melanogrammus aeglefinus, family Gadidae, order Gadiformes). The entire mitogenomes were amplified and sequenced by primer walking using newly designed specific internal primers. Lengths were 16,569 and 16,585 bases for whiting and haddock respectively, lengths which lie within the range of previously reported gadiform sequences from Atlantic cod (Gadus morhua, 16,696 bases) and walleye pollock (Theragra chalcogramma, 16,570 bases). Gene arrangement in both species conformed to the order seen in most vertebrate mitochondrial genomes. We identified a long intergenic spacer located between the tRNA(Thr) and tRNA(Pro) genes (of 100 and 70 bp long for whiting and haddock, respectively), as previously described for other species of the order Gadiformes. Using nucleotide and amino acid divergence data of four complete gadoid mitogenomes (M. merlangius, M. aeglefinus, G. morhua and T. chalcogramma), we examined in detail the relative mtDNA mutation patterns across genes and among Gadidae species and tested for the performance of each protein-coding, transfer RNA and ribosomal RNA gene in depicting the expected phylogeny among the four species, as compared with the whole genome dataset. This comparison may be particularly useful in phylogenetic analyses of such a diverse fish family, as well as for the understanding of the patterns of nucleotide substitution of the mtDNA at low levels of divergence.

Two-factor design for coagulant/flocculant doses effect for solid-liquid separation of dairy manure

Screened dairy manure, with a total solids content equal to 34.7 g TS l(-1), was subjected to a coagulation-flocculation treatment using FeCl, as coagulant and a medium cationic polyacrylamide (MCP1). The effect of changing doses of the additives (FeCl3 and MCP1) on the properties of supernatant fractions was studied by means of design of response surface using "Statgraphics Plus 3.0" program. The results showed that the values of concentrations found in supernatants obtained after settling of the flocs for two of the dependent variables studied, filtrate chemical oxygen demand (CODf) and total organic carbon (TOC), were significantly influenced by both the FeCl3 and MCP1 doses at an error lower than 5%. The values of concentrations of the remaining variables studied (TS, VS, CODt, CODvfa) were significantly influenced only by the MCP1 dose at an error lower than 5%. The predictive model obtained the best satisfactory parameters for TOC supernatant's concentration (R2=0.980, F-ratio = 438.89 (p-value < 0.05)) and the worse for VS (R2 = 0.783, F-ratio = 33.43 (p-value < 0.05)).

TaqMan DNA technology confirms likely overestimation of cod (Gadus morhua L.) egg abundance in the Irish Sea: implications for the assessment of the cod stock and mapping of spawning areas using egg-based methods

Recent substantial declines in northeastern Atlantic cod stocks necessitate improved biological knowledge and the development of techniques to complement standard stock assessment methods (which largely depend on accurate commercial catch data). In 2003, an ichthyoplankton survey was undertaken in the Irish Sea and subsamples of 'cod-like' eggs were analysed using a TaqMan multiplex, PCR (polymerase chain reaction) assay (with specific probes for cod, haddock and whiting). The TaqMan method was readily applied to the large number of samples (n = 2770) generated during the survey and when combined with a manual DNA extraction protocol had a low failure rate of 6%. Of the early stage 'cod-like' eggs (1.2-1.75 mm diameter) positively identified: 34% were cod, 8% haddock and 58% whiting. As previous stock estimates based on egg surveys for Irish Sea cod assumed that the majority of 'cod-like' eggs were from cod, the TaqMan results confirm that there was probably substantial contamination by eggs of whiting and haddock that would have inflated estimates of the stock biomass.

NONLINEAR EFFECTS OF FEMALE MATE CHOICE IN WILD THREESPINE STICKLEBACKS

Sexual selection by mate choice represents a very important selective pressure in many animal species and might have evolutionary impacts beyond exaggeration of secondary sexual traits. Describing the shape and strength of the relationships linking mating success and nonsexual traits in natural conditions represents a challenging step in our understanding of adaptive evolution. We studied the effect of behavioral (nest site choice), immunological (trematode level of infection), genetic diversity (measured by mean d2) and morphological (standard length and pectoral fin size) traits on male mating success in a natural population of threespine sticklebacks Gasterosteaus aculeatus. Male mating success was measured by microsatellite genotyping of embryos used to infer female genotypes. First, we analyzed all territorial males (full analysis) but also considered independently only males with a nonzero mating success (reduced analysis) because some of the males with no eggs could have been part of a later breeding cycle. Multiple linear regressions identified a significant negative effect of parasite load in the full analysis, whereas no linear effect was found in the reduced analysis. The quadratic analyses revealed that nest location and parasite load were significantly related to mating success by positive (concave selection) and negative (convex selection) quadratic coefficients respectively, resulting in a saddle-shaped fitness surface. Moreover, there were significant interactions between nest location, mean d2 and parasite load in the reduced analysis. The subsequent canonical rotation of the matrix of quadratic and cross-product terms identified two major axes of the response surface: a vector representing mostly nest site choice and a vector representing parasite load. These results imply that there exists more than one way for a male threespine stickleback to maximize its mating success and that such nonlinear relationships between male mating success induced by female mate choice and male characteristics might have been overlooked in many studies.

Variation in habitat preference and population structure among three species of the Lake Malawi cichlid genus Protomelas

Several studies have demonstrated strong population structuring over small distances in the rocky-shore mbuna cichlid fishes from Lake Malawi, suggesting the potential for allopatric speciation. However, many endemic Lake Malawi cichlids are neither mbuna, nor confined to rocky shores. Using microsatellites, we investigated the population structure in three species of the non-mbuna genus Protomelas. The rocky-shore P. taeniolatus showed high levels of population structure even over distances of less than 1 km, while the sandy-shore species P. similis showed no significant structure over distances up to 21 km. Protomelas fenestratus, which is generally found at the interface between rocks and sand, also showed low levels of population structure. Our results suggest that the model of allopatric speciation based on habitat fragmentation within the current lake basin may be equally applicable to rocky-shore non-mbuna as to mbuna, but that an alternative model is required to explain speciation among sandy-shore species as well as the deep-water and pelagic species.

Genetic mosaic in a marine species flock

We used molecular approaches to study the status of speciation in coral reef fishes known as hamlets (Serranidae: Hypoplectrus). Several hamlet morphospecies coexist on Caribbean reefs, and mate assortatively with respect to their strikingly distinct colour patterns. We provide evidence that, genetically, the hamlets display characteristics common in species flocks on land and in freshwaters. Substitutions within two mitochondrial DNA (mtDNA) protein-coding genes place hamlets within a monophyletic group relative to members of two related genera (Serranus and Diplectrum), and establish that the hamlet radiation must have been very recent. mtDNA distances separating hamlet morphospecies were slight (0.6 +/- 0.04%), yielding a coalescent estimate for the age of the hamlet flock of approximately 430 000 years. Morphospecies did not sort into distinct mtDNA haplotype phylogroups, and alleles at five hypervariable microsatellite loci were shared broadly across species boundaries. None the less, molecular variation was not distributed at random. Analyses of mtDNA haplotype frequencies and nested clades in haplotype networks revealed significant genetic differences between geographical regions and among colour morphospecies. We also observed significant microsatellite differentiation between geographical regions and in Puerto Rico, among colour morphospecies; the latter providing evidence for reproductive isolation between colour morphospecies at this locale. In our Panama collection, however, colour morphospecies were mostly genetically indistinguishable. This mosaic pattern of DNA differentiation implies a complex interaction between population history, mating behaviour and geography and suggests that porous boundaries separate species in this flock of brilliantly coloured coral reef fishes.

Evidence for genetic monogamy and female-biased dispersal in the biparental mouthbrooding cichlid Eretmodus cyanostictus from Lake Tanganyika

In this study, we investigate whether apparent social monogamy (where a species forms a pair bond but may participate in copulations outside the pair bond) corresponds with genetic monogamy (where individuals participate only in copulations within a pair bond) in a biparental mouthbrooding cichlid fish, Eretmodus cyanostictus, from Lake Tanganyika, Africa. Our findings suggest that E. cyanostictus is both socially and genetically monogamous and that monogamy may result from limited opportunities for polygyny, rather than from reproductive benefits of monogamy. Mating systems are believed to influence the relative rate of dispersal of the sexes, and our results suggest that E. cyanostictus displays female-biased dispersal, providing some support for the 'resource competition' hypothesis driving sex-biased dispersal.

No evidence for parallel sympatric speciation in cichlid species of the genus Pseudotropheus from north-western Lake Malawi

To test the hypothesis of parallel speciation by sexual selection, we examined length variation at six microsatellite loci of samples from four sites of four to six putative species belonging to two subgenera of rocky shore mbuna cichlids from Lake Malawi. Almost all fixation indices were significantly different from zero, suggesting that there is presently little or no gene flow among allopatric populations or sympatric species. Analysis of variance indicated that genetic distances among allopatric populations of putative conspecifics were significantly lower than among sympatric populations of heterospecifics. The topology of trees based on distance matrices was also largely consistent with the hypothesis that the putative species are monophyletic and have thus not evolved in parallel in their present locations. If parallel speciation does occur in Malawi cichlids, it may be on a larger spatial scale than investigated in our study.

Molecular systematics and biogeography of the Neotropical monkey genus, Alouatta

We take advantage of the broad distribution of howler monkeys from Mexico to Argentina to provide a historical biogeographical analysis on a regional scale that encompasses the entire Neotropics. The phylogenetic relationships among 9 of the 10 recognized Alouatta species were inferred using three mitochondrial and two nuclear genes. The nuclear gene regions provided no phylogenetic resolution among howler monkey species, and were characterized by very low levels of sequence divergence between Alouatta and the Ateles outgroup. The mtDNA genes, on the other hand, produced a well-resolved phylogeny, which indicated that the earliest split among howler monkeys separated cis- and trans-Andean clades. Eight monophyletic mtDNA haplotype clades were identified, representing six named species in South America, including Alouatta seniculus, Alouatta sara, Alouatta macconelli, Alouatta caraya, Alouatta belzebul, and Alouatta guariba, and two in Mesoamerica, Alouatta pigra and Alouatta palliata. Molecular clock-based estimates of branching times indicated that contemporary howler monkey species originated in the late Miocene and Pliocene, not the Pleistocene. The causes of Alouatta diversification were more difficult to pin down, although we posit that the initial cis-, trans-Andean split in the genus was caused by the late Miocene completion of the northern Andes. Riverine barriers to dispersal and putative forest refuges can neither be discounted nor distinguished as causes of speciation in many cases, and one, the other or both have likely played a role in the diversification of South American howler monkeys. Finally, we estimated the separation of Mesoamerican A. pigra and A. palliata at 3Ma, which corresponds to the completion date of the Panama Isthmus promoting a role for this earth history event in the speciation of Central American howler monkeys.