Co-management and Traditional Fisheries: The Case of Fante Fishers in Elmina, Ghana

Co-management has widely been recognized as an alternative approach to addressing natural resource crises and diverse environmental concerns. In line with this, the Ghanaian fishery sector introduced co-management as an institutional approach to manage natural resources. However, studies still reiterate that, the traditional fishery sector is still in decline, which have affected the livelihood of communities that depends on the resource and resulted in Ghana becoming a net importer to meet the country’s fish requirements, which is likely to increase due to the growing population. The aim of this study therefore is to understand the factors contributing to the decline of the sector despite the adoption of co-management. Following a qualitative approach, the study involved Fante fishers in Elmina to understand how co-management have influenced traditional fishing. The study further seeks to identify constraints that impede the successful implementation of co-management. By exploring the economic, social and environmental impacts of co-management, divergent issues were raised from respondents. Research findings reveals that weak institutional framework, lack of active participation, empowerment and trust as the challenges that contributes to the underperformance of co-management. From discussions and analysis, general lessons and recommendations are drawn from the study

Exploring typhoon variability over the mid-to-late Holocene : evidence of extreme coastal flooding from Kamikoshiki, Japan

Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Quaternary Science Reviews 28 (2009): 1774-1785, doi:10.1016/j.quascirev.2009.02.005.Sediment cores from two coastal lakes located on the island of Kamikoshiki in southwestern Japan (Lake Namakoike and Lake Kaiike) provide evidence for the response of a backbarrier beach system to episodic coastal inundation over the last 6400 years. Subbottom seismic surveys exhibit acoustically laminated, parallel to subparallel seismic reflectors, intermittently truncated by erosional unconformities. Sediment cores collected from targeted depocenters in both lakes contain finely laminated organic mud interbedded with coarse grained units, with depths of coarse deposits concurrent with prominent seismic reflectors. The timing of the youngest deposit at Kamikoshiki correlates to the most recently documented breach in the barrier during a typhoon in 1951 AD. Assuming this modern deposit provides an analog for identifying past events, paleo typhoons may be reconstructed from layers exhibiting an increase in grain-size, a break in fine-scale stratigraphy, and elevated Sr concentrations. Periods of barrier breaching are concurrent with an increase in El Niño frequency, indicating that the El Niño/Southern Oscillation has potentially played a key role in governing typhoon variability during the mid-to-late Holocene. An inverse correlation is observed between tropical cyclone reconstructions from the western North Atlantic and the Kamikoshiki site, which may indicate an oscillating pattern in tropical cyclone activity between the western Northern Atlantic and the western North Pacific, or at least between the western Northern Atlantic and regions encompassing southern Japan. The two kamikaze typhoons which contributed to the failed Mongol invasions of Japan in 1274 AD and 1281 AD occur during a period with more frequent marine-sourced deposition at the site, suggesting the events took place during a period of greater regional typhoon activity.The study was supported by the Coastal Ocean Institute (COI) and the Ocean and Climate Change Institute (OCCI) at Woods Hole Oceanographic Institute

Evidence for a clade composed of molluscs with serially repeated structures: Monoplacophorans are related to chitons

Monoplacophorans are among the rarest members of the phylum Mollusca. Previously only known from fossils since the Cambrian, the first living monoplacophoran was discovered during the famous second Galathea deep-sea expedition. The anatomy of these molluscs shocked the zoological community for presenting serially repeated gills, nephridia, and eight sets of dorsoventral pedal retractor muscles. Seriality of organs in supposedly independent molluscan lineages, i.e., in chitons and the deep-sea living fossil monoplacophorans, was assumed to be a relict of ancestral molluscan segmentation and was commonly accepted to support a direct relationship with annelids. We were able to obtain one specimen of a monoplacophoran Antarctic deep-sea species for molecular study. The first molecular data on monoplacophorans, analyzed together with the largest data set of molluscs ever assembled, clearly illustrate that monoplacophorans and chitons form a clade. This “Serialia” concept may revolutionize molluscan systematics and may have important implications for metazoan evolution as it allows for new interpretations for primitive segmentation in molluscs.Organismic and Evolutionary Biolog

Cardiotoxicidade por cocaína e disfunção ventricular em paciente jovem

The use of psychoactive substances can induce cardiovascular complications. The purpose of this report is to describe the case of a young patient with dilated cardiomyopathy secondary to cocaine use. Patient with dyspnea for six months, with progressive worsening, paroxysmal nocturnal dyspnea, orthopnea, and lower limb edema. Physical examination showed tachycardia (110 bpm), with other vital signs without alterations, presence of crackling rales in the bases and middle fields, moderate volume ascites, and significant lower limb edema. Electrocardiogram showed sinus rhythm with left chamber overload; chest X-ray only marked cardiomegaly. The echocardiogram showed reduced left ventricular (LV) ejection fraction (7%), enlarged left atrium, and right ventricle (RV), with eccentric hypertrophy and severe left ventricular systolic dysfunction, with moderate RV dysfunction and pulmonary hypertension (39 mmHg). Resonance presented mild right atrial dilatation, RV with significant dilatation, significant biventricular systolic dysfunction, with diffuse hypokinesia, and myocardial fibrosis of non-coronary pattern. The reported case shows a diagnosis whose pathophysiological mechanism of dilated cardiomyopathy is not clear. The most coherent association of dilated cardiomyopathy presented by the patient is related to cocaine abuse, due to the long-term recurrent stimulus that excess catecholamines caused in the myocardium. Given the spectrum of cardiomyopathy, infarction, and arrhythmias that may potentially occur associated with cocaine use, the hypothesis of cardiotoxicity should be considered in the evaluation of a patient with a history of cocaine abuse.O uso de substâncias psicoativas pode induzir complicações cardiovasculares. O objetivo deste relato é descrever o caso de um paciente jovem com cardiomiopatia dilatada secundária ao uso de cocaína. Paciente com dispneia há seis meses, com piora progressiva, dispneia paroxística noturna, ortopneia e edema de membros inferiores. Ao exame físico apresentava taquicardia (110 bpm), com demais sinais vitais sem alterações, presença de estertores crepitantes em bases e campos médios, ascite de moderado volume e edema importante de membros inferiores. No eletrocardiograma, apresentava ritmo sinusal com sobrecarga de câmaras esquerdas; na radiografia de tórax, apenas cardiomegalia acentuada. O ecocardiograma evidenciou fração de ejeção (FE) do ventrículo esquerdo (VE) reduzida (7%), aumento de átrio esquerdo e ventrículo direito (VD), com hipertrofia excêntrica e disfunção sistólica acentuada do VE, com disfunção moderada do VD e hipertensão pulmonar (39 mmHg). Na ressonância, apresentou dilatação discreta do átrio direito, VD com dilatação importante, disfunção sistólica biventricular importante, com hipocinesia difusa (FE 8% de VD), além de fibrose miocárdica de padrão não coronariano inferosseptal. O caso relatado evidencia um diagnóstico cujo mecanismo fisiopatológico da cardiomiopatia dilatada não está claro. A associação mais coerente da cardiomiopatia dilatada apresentada pelo paciente está relacionada ao uso abusivo de cocaína, devido ao estímulo recorrente e de longa duração que o excesso de catecolaminas provocou no miocárdio. Tendo em vista o espectro de cardiomiopatia, infarto e arritmias que potencialmente podem ocorrer associados ao uso de cocaína, deve-se considerar a hipótese de cardiotoxicidade na avaliação de paciente com história de abuso de cocaína.  

Escherichia coli mar and acrAB Mutants Display No Tolerance to Simple Alcohols

The inducible Mar phenotype of Escherichia coli is associated with increased tolerance to multiple hydrophobic antibiotics as well as some highly hydrophobic organic solvents such as cyclohexane, mediated mainly through the AcrAB/TolC efflux system. The influence of water miscible alcohols ethanol and 1-propanol on a Mar constitutive mutant and a mar deletion mutant of E. coli K-12, as well as the corresponding strains carrying the additional acrAB deletion, was investigated. In contrast to hydrophobic solvents, all strains were killed in exponential phase by 1-propanol and ethanol at rates comparable to the parent strain. Thus, the Mar phenotype does not protect E. coli from killing by these more polar solvents. Surprisingly, AcrAB does not contribute to an increased alcohol tolerance. In addition, sodium salicylate, at concentrations known to induce the mar operon, was unable to increase 1-propanol or ethanol tolerance. Rather, the toxicity of both solvents was increased in the presence of sodium salicylate. Collectively, the results imply that the resilience of E. coli to water miscible alcohols, in contrast to more hydrophobic solvents, does not depend upon the AcrAB/TolC efflux system, and suggests a lower limit for substrate molecular size and functionality. Implications for the application of microbiological systems in environments containing high contents of water miscible organic solvents, e.g., phage display screening, are discussed

Replication Fork Reactivation in a dnaC2 Mutant at Non-Permissive Temperature in Escherichia coli

Replicative helicases unwind double-stranded DNA in front of the polymerase and ensure the processivity of DNA synthesis. In Escherichia coli, the helicase loader DnaC as well as factors involved in the formation of the open complex during the initiation of replication and primosomal proteins during the reactivation of arrested replication forks are required to recruit and deposit the replicative helicase onto single-stranded DNA prior to the formation of the replisome. dnaC2 is a thermosensitive allele of the gene specifying the helicase loader; at non-permissive temperature replication cannot initiate, but most ongoing rounds of replication continues through to completion (18% of dnaC2 cells fail to complete replication at non-permissive temperature). An assumption, which may be drawn from this observation, is that only a few replication forks are arrested under normal growth conditions. This assumption, however, is at odds with the severe and deleterious phenotypes associated with a null mutant of priA, the gene encoding a helicase implicated in the reactivation of arrested replication forks. We developed an assay that involves an abrupt inactivation of rounds of synchronized replication in a large population of cells, in order to evaluate the ability of dnaC2 cells to reactivate arrested replication forks at non-permissive temperature. We compared the rate at which arrested replication forks accumulated in dnaC2 priA+ and dnaC2 priA2 cells and observed that this rate was lower in dnaC2 priA+ cells. We conclude that while replication cannot initiate in a dnaC2 mutant at non-permissive temperature, a class of arrested replication forks (PriA-dependent and DnaC-independent) are reactivated within these cells

Comparative Analysis of Chromosome Counts Infers Three Paleopolyploidies in the Mollusca

The study of paleopolyploidies requires the comparison of multiple whole genome sequences. If the branches of a phylogeny on which a whole-genome duplication (WGD) occurred could be identified before genome sequencing, taxa could be selected that provided a better assessment of that genome duplication. Here, we describe a likelihood model in which the number of chromosomes in a genome evolves according to a Markov process with one rate of chromosome duplication and loss that is proportional to the number of chromosomes in the genome and another stochastic rate at which every chromosome in the genome could duplicate in a single event. We compare the maximum likelihoods of a model in which the genome duplication rate varies to one in which it is fixed at zero using the Akaike information criterion, to determine if a model with WGDs is a good fit for the data. Once it has been determined that the data does fit the WGD model, we infer the phylogenetic position of paleopolyploidies by calculating the posterior probability that a WGD occurred on each branch of the taxon tree. Here, we apply this model to a molluscan tree represented by 124 taxa and infer three putative WGD events. In the Gastropoda, we identify a single branch within the Hypsogastropoda and one of two branches at the base of the Stylommatophora. We also identify one or two branches near the base of the Cephalopoda

Adaptive modulation of antibiotic resistance through intragenomic coevolution

Bacteria gain antibiotic resistance genes by horizontal acquisition of mobile genetic elements (MGEs) from other lineages. Newly acquired MGEs are often poorly adapted causing intragenomic conflicts; these are resolved by either compensatory adaptation - of the chromosome or the MGE - or reciprocal coadaptation. The footprints of such intragenomic coevolution are present in bacterial genomes, suggesting an important role promoting genomic integration of horizontally acquired genes, but direct experimental evidence of the process is limited. Here we show adaptive modulation of tetracycline resistance via intragenomic coevolution between Escherichia coli and the multidrug resistant plasmid RK2. Tetracycline treatments, including monotherapy or combination therapies with ampicillin, favoured de novo chromosomal resistance mutations coupled with mutations on RK2 impairing the plasmid-encoded tetracycline efflux pump. These mutations together provided increased tetracycline resistance at reduced cost. Additionally, the chromosomal resistance mutations conferred cross-resistance to chloramphenicol. Reciprocal coadaptation was not observed under ampicillin-only or no antibiotic selection. Intragenomic coevolution can create genomes comprising multiple replicons that together provide high-level, low-cost resistance, but the resulting co-dependence may limit the spread of coadapted MGEs to other lineages