Cytological and isoenzyme analysis of the Bucay and Quevedo cytotypes of the onchocerciasis vector Simulium exiguum (Diptera: Simuliidae) in Ecuador

Four cytotypes of Simulium exiguum occur in Ecuador, where this morphospecies is the primary vector of onchocerciasis. In this paper, we give the first full description of the banding pattern of the larval polytene chromosomes of the Quevedo cytotypes differ from the chromosomal standard sequence (of the Cayapa cytotype) by the fixed inversions IIL-5 and IIL-6. The Quevedo cytotype additionally differs from the standard and Bucay cytotypes by processing a differentiated X chromosome, wich is indicated by the inversion IIS-A. As the degree of reproductive isolation between the Bucay and Quevedo cytotypes has not yet been estabilished, they must be regarded as intraspecific variants of the same species. In fact, isoenzyme characterizations showed that the Bucay and Quevedo cytotypes are differentiated only to the extent expected of incipient species or geographical populations. Moreover, the sibiling species status previously given to the Bucay cytotype needs be reassessed, there being inadequate analysis from areas in Ecuador where Bucay occurs in sympatry with the standard Cayapa cytotype. No isoenzyme electromorphs were discovered that identified all or mostadult females of any one (cytotype-pure) collection.

Aproximació a la figura dels Business Angels

Els business angels són persones físiques que inverteixen una part dels seus diners en empreses joves, tot just acabades de crear, en alguns casos fins i tot ajuden a crear-les. El nom d’àngels té el seu origen en els rics filantrops de Nova York que finançaven les obres que s’estrenaven a Broadway. Aquests filantrops invertien els seus diners en una obra de teatre, pel plaer de contribuir a la cultura, molt sovint no arribaven a recuperar mai aquests diners. Els business angels, no són filantrops, inverteixen esperant guanyar diners, però al igual que els àngels de Broadway, els mou alguna cosa més que els diners, ja que està àmpliament documentat que darrera d’aquestes inversions hi ha també raons no financeres, com ara fomentar l’esperit emprenedor o fins i tot la cerca de diversió. Podríem dir que el terme “business angel” es va encunyar a principis dels 80 als EUA, per tant aviat farà 30 anys, no obstant, encara avui, la majoria de catalans no coneixen el significat d’aquest terme. A Catalunya i Espanya anem terriblement retardats en l’estudi i la promoció d’aquesta figura en relació a països com els EUA i el Regne Unit, però també massa enrera en relació a països com Finlàndia, Suècia, Noruega i Alemanya. L’objectiu d’aquest treball és doncs oferir una complerta aproximació a aquesta figura del business angel, una figura que entenem clau en el desenvolupament empresarial i per tant una figura que cal potenciar a tots els nivells. Per tal de contextualitzar aquesta important figura, el treball parteix de l’anàlisi de la relació existent entre emprenedoria i creixement econòmic, s’endinsa després en el capital risc, per presentar finalment qui és i que fa el business angel. El treball intenta també mostrar l’abús d’usos i la inconsistència de les definicions que es donen del terme “business angel” i per tant la gran confusió que tot això genera.

Investor protection and income inequality: risk sharing vs risk taking

This paper studies the relationship between investor protection, entrepreneurial risk taking and income inequality. In the presence of market frictions, better protection makes investors more willing to take on entrepreneurial risk when lending to firms, thereby improving the degree of risk sharing between financiers and entrepreneurs. On the other hand, by increasing risk sharing, investor protection also induces more firms to undertake risky projects. By increasing entrepreneurial risk taking, it raises income dispersion. By reducing the risk faced by entrepreneurs, it reduces income volatility. As a result, investor protection raises income inequality to the extent that it fosters risk taking, while it reduces it for a given level of risk taking. Empirical evidence from a panel of forty-five countries spanning the period 1976-2000 supports the predictions of the model.

Accounting conservatism and firm investment efficiency

Conservatism, through the timelier recognition of losses in the income statement, is expected to increase firm investment efficiency through three main channels: (1) by decreasing the adverse effect of information asymmetries between outside equity holders and managers, facilitating the monitoring of managerial investment decisions; (2) by increasing managerial incentives to abandon poorly performing projects earlier and to undertake fewer negative net present-value investments; and (3) by facilitating the access to external financing at lower cost. Using a large US sample for the period 1990-2007 we find a negative association between conservatism and measures of over- and under- investment, and a positive association between conservatism and future profitability. This is consistent with firms reporting more conservative numbers investing more efficiently and in more profitable projects. Our results add to a growing stream of literature suggesting that eliminating conservatism from accounting regulatory frameworks may lead to undesirable economic consequences.

The Polytene Chromosomes of Cnesia dissimilis (Edwards) and Three Species of Gigantodax Enderlein (Diptera: Simuliidae) from Lanin National Park (Argentina)

Cytological studies were made on larvae of Gigantodax marginalis, G. chilensis, G. fulvescens and Cnesia dissimilis from four creeks in Lanin National Park, Neuquen province, Argentina. Chromosome maps and idiograms of these species are presented. The following inversions were observed: G. marginalis: IL-1 (X-linked inversion), IL-2 (Y-linked inversion), IIS-1.2, IIL-1, IIIL-4,5; G. chilensis: IL-4 (X-linked inversion), IIS-1.2, IIIL-4,5; G. fulvescens:IL-1 (X-linked inversion), IL-3 (Y-linked inversion), IIS-1.2, IIL-1, IIIL-4,5; C. dissimilis: IL-1, IL-5, IIIL-1. Karyological information was used to construct a cladogram and Cnesia sp. Was found to show close resemblance to the three Gigantodax spp.

The borehole-fluid effect in electrical resistivity imaging

Fluid that fills boreholes in crosswell electrical resistivity investigations provides the necessary electrical contact between the electrodes and the rock formation but it is also the source of image artifacts in standard inversions that do not account for the effects of the boreholes. The image distortions can be severe for large resistivity contrasts between the rock formation and borehole fluid and for large borehole diameters. We have carried out 3D finite-element modeling using an unstructured-grid approach to quantify the magnitude of borehole effects for different resistivity contrasts, borehole diameters, and electrode configurations. Relatively common resistivity contrasts of 100:1 and borehole diameters of 10 and 20 cm yielded, for a bipole length of 5 m, apparent resistivity underestimates of approximately 12% and 32% when using AB-MN configurations and apparent resistivity overestimates of approximately 24% and 95% when using AM-BN configurations. Effects are generally more severe at shorter bipole spacings. We report the results obtained by either including or ignoring the boreholes in inversions of 3D field data from a test site in Switzerland, where approximately 10,000 crosswell resistivity-tomography measurements were made across six acquisition planes among four boreholes. Inversions of raw data that ignored the boreholes filled with low-resistivity fluid paradoxically produced high-resistivity artifacts around the boreholes. Including correction factors based on the modeling results fora ID model with and without the boreholes did not markedly improve the images. The only satisfactory approach was to use a 3D inversion code that explicitly incorporated the boreholes in the actual inversion. This new approach yielded an electrical resistivity image that was devoid of artifacts around the boreholes and that correlated well with coincident crosswell radar images.

Novel H3K4me3 marks are enriched at human- and chimpanzee-specific cytogenetic structures.

Human and chimpanzee genomes are 98.8% identical within comparable sequences. However, they differ structurally in nine pericentric inversions, one fusion that originated human chromosome 2, and content and localization of heterochromatin and lineage-specific segmental duplications. The possible functional consequences of these cytogenetic and structural differences are not fully understood and their possible involvement in speciation remains unclear. We show that subtelomeric regions-regions that have a species-specific organization, are more divergent in sequence, and are enriched in genes and recombination hotspots-are significantly enriched for species-specific histone modifications that decorate transcription start sites in different tissues in both human and chimpanzee. The human lineage-specific chromosome 2 fusion point and ancestral centromere locus as well as chromosome 1 and 18 pericentric inversion breakpoints showed enrichment of human-specific H3K4me3 peaks in the prefrontal cortex. Our results reveal an association between plastic regions and potential novel regulatory elements.

Incorporació de criteris d’eficiència en les dissolucions matrimonials a Catalunya: estudi comparatiu amb el dret de familia de l’Estat de Nova York

El règim econòmic matrimonial català i el de l’estat de Nova York presenten un paral·lelisme estructural important ja que tots dos territoris han adoptat el mateix règim econòmic matrimonial, el de separació de béns. No obstant, la seva implementació i la conseqüent pràctica jurisprudencial difereix significativament. El dret de família de l’estat de Nova York, se situa en un context de common law, és a dir, en un sistema judicial que evoluciona ràpidament i s’adapta relativament ràpid a les necessitats d’una realitat social que està en constant evolució. El legislador català, tot i que ha fet esforços a nivell de donar respostes als nous reptes plantejat per la realitat familiar catalana, encara està lluny de fer front a problemes d’aplicació que sovint planteja el règim econòmic matrimonial dels cònjuges catalans. D’altra banda, la realitat social catalana no és significativament diferent a la realitat nord-americana ateses les noves composicions familiars amb famílies monoparentals, fills de diferents matrimonis i una alta proporció de divorcis per matrimoni. D’altra banda, l’estructura patrimonial de les famílies, tant les catalanes com les novaiorqueses també presenten una estructura patrimonial similar formada no només per la residència habitual sinó per patrimoni intangible i per inversions que comencen a meritar durant el matrimoni però que vencen una vegada aquest vincle s’ha dissolt. Ha resultat constructiu, doncs, comparar els règims i extreure lliçons del règim novaiorquès que s’han revelat molt útils per a la nostra pràctica catalana. Així doncs, l’objectiu d’aquest projecte de recerca ha estat estudiar el règim econòmic matrimonial català i el novaiorquès que ha culminat amb la formulació de propostes normatives i de pràctica jurisprudencial que permetran modernitzar i actualitzar l’aplicació del règim econòmic matrimonial català i d’aquesta manera adaptar-lo a la nova realitat social i econòmica de les famílies catalanes.

Polytene chromosome map and inversion polymorphism in Drosophila mediopunctata

Drosophila mediopunctata belongs to the tripunctata group, and is one of the commonest Drosophila species collected in some places in Brazil, especially in the winter. A standard map of the polytene chromosomes is presented. The breakpoints of the naturally occurring chromosomal rearrangements are marked on the map. The distribution of breaking points through the chromosomes of D. mediopunctata is apparently non-random. Chromosomes X, II and IV show inversion polymorphisms. Chromosome II is the most polymorphic, with 17 inversions, 8 inversions in the distal region and 9 in the proximal region. Chromosome X has four different gene arrangements, while chromosome IV has only two.

The fine-scale architecture of structural variants in 17 mouse genomes.

BACKGROUND: Accurate catalogs of structural variants (SVs) in mammalian genomes are necessary to elucidate the potential mechanisms that drive SV formation and to assess their functional impact. Next generation sequencing methods for SV detection are an advance on array-based methods, but are almost exclusively limited to four basic types: deletions, insertions, inversions and copy number gains. RESULTS: By visual inspection of 100 Mbp of genome to which next generation sequence data from 17 inbred mouse strains had been aligned, we identify and interpret 21 paired-end mapping patterns, which we validate by PCR. These paired-end mapping patterns reveal a greater diversity and complexity in SVs than previously recognized. In addition, Sanger-based sequence analysis of 4,176 breakpoints at 261 SV sites reveal additional complexity at approximately a quarter of structural variants analyzed. We find micro-deletions and micro-insertions at SV breakpoints, ranging from 1 to 107 bp, and SNPs that extend breakpoint micro-homology and may catalyze SV formation. CONCLUSIONS: An integrative approach using experimental analyses to train computational SV calling is essential for the accurate resolution of the architecture of SVs. We find considerable complexity in SV formation; about a quarter of SVs in the mouse are composed of a complex mixture of deletion, insertion, inversion and copy number gain. Computational methods can be adapted to identify most paired-end mapping patterns.

Cytotaxonomy of Simulium cauchense Floch & Abonnenc and Simulium quadrifidum Lutz (Diptera: Simuliidae) in Brazilian Amazonia

Simulium cauchense Floch & Abonnenc and Simulium quadrifidum Lutz are widely distributed in the Amazon region and are morphologically similar at the larval and pupal stages. Chromosomally, these species are readily distinguished by the position of the nucleolar organizer, which is in the short arm of chromosome I in S. cauchense and in the long arm of chromosomes III in S. quadrifidum. They also differ by three fixed inversions. Sex chromosomes are undifferentiated in both species. Chromosomal resolution of the two species allowed us to evaluate four structural features previously used as diagnostic aids at the larval stage. Characters that distinguish larvae of the two species are the number of branches and branching patterns of the dorsal abdominal setae and the dark band on each primary fan. Branching patterns of the gill histoblasts were often diagnostic, with S. quadrifidum exhibiting more proximal branching and S. cauchense more distal branching. Sites where both species occurred sometimes had larvae with one petiole branching proximally and the other distally; in these cases examination of the chromosomes permitted assignment of the specimen to species. Pigmentation patterns of larvae, on the other hand, are highly variable. Color typically is sex linked in both species.

Imaging and quantifying salt-tracer transport in a riparian groundwater system by means of 3D ERT monitoring

Determining groundwater flow paths of infiltrated river water is necessary for studying biochemical processes in the riparian zone, but their characterization is complicated by strong temporal and spatial heterogeneity. We investigated to what extent repeat 3D surface electrical resistance tomography (ERT) can be used to monitor transport of a salt-tracer plume under close to natural gradient conditions. The aim is to estimate groundwater flow velocities and pathways at a site located within a riparian groundwater system adjacent to the perialpine Thur River in northeastern Switzerland. Our ERT time-lapse images provide constraints on the plume's shape, flow direction, and velocity. These images allow the movement of the plume to be followed for 35 m. Although the hydraulic gradient is only 1.43 parts per thousand, the ERT time-lapse images demonstrate that the plume's center of mass and its front propagate with velocities of 2x10(-4) m/s and 5x10(-4) m/s, respectively. These velocities are compatible with groundwater resistivity monitoring data in two observation wells 5 m from the injection well. Five additional sensors in the 5-30 m distance range did not detect the plume. Comparison of the ERT time-lapse images with a groundwater transport model and time-lapse inversions of synthetic ERT data indicate that the movement of the plume can be described for the first 6 h after injection by a uniform transport model. Subsurface heterogeneity causes a change of the plume's direction and velocity at later times. Our results demonstrate the effectiveness of using time-lapse 3D surface ERT to monitor flow pathways in a challenging perialpine environment over larger scales than is practically possible with crosshole 3D ERT.

The Growing Importance of CNVs: New Insights for Detection and Clinical Interpretation.

Differences between genomes can be due to single nucleotide variants, translocations, inversions, and copy number variants (CNVs, gain or loss of DNA). The latter can range from sub-microscopic events to complete chromosomal aneuploidies. Small CNVs are often benign but those larger than 500 kb are strongly associated with morbid consequences such as developmental disorders and cancer. Detecting CNVs within and between populations is essential to better understand the plasticity of our genome and to elucidate its possible contribution to disease. Hence there is a need for better-tailored and more robust tools for the detection and genome-wide analyses of CNVs. While a link between a given CNV and a disease may have often been established, the relative CNV contribution to disease progression and impact on drug response is not necessarily understood. In this review we discuss the progress, challenges, and limitations that occur at different stages of CNV analysis from the detection (using DNA microarrays and next-generation sequencing) and identification of recurrent CNVs to the association with phenotypes. We emphasize the importance of germline CNVs and propose strategies to aid clinicians to better interpret structural variations and assess their clinical implications.

Catalunya i la Comunitat de Madrid com a pols d'atracció de la inversió estrangera directa procedent de l'Asia Oriental (1996-2004)

Aquest document descriu els valors d'inversió estrangera directa de l'Àsia oriental a escala mundial durant el període 1996-2004, per a valorar la dimensió d'aquest tipus d'inversió a Catalunya i a Madrid. Relaciona els valors d'aquesta inversió amb les taxes de comerç exterior amb l'Àsia oriental i amb els valors d'immigració asiàtica a Catalunya i a Madrid.

China y la globalización del mercado automovilístico : efectos sobre las empresas catalanas de componentes

Estudi centrat en el sector de components d'algunes empreses catalanes que tendeixen a buscar inversions en els països asiàtics com a mesura d'adaptació al nou ordre, mitjançant la seva unió amb empreses locals del país destinació conegudes com joint-ventures.