981 resultados para Axon morphometry
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The age and growth, length – weight relationship and relative condition factor of Gerres filamentosus (Cuvier, 1829) from Kodungallur, Azhikode Estuary were studied by examination of 396 specimens collected between May 2008 to October 2008. Here, length frequency method was used to study age and growth in fishes. L∞, K and t 0 obtained from seasonal and non - seasonal growth curves. Gerres filamentosus showed a low mortality rate (Z) 3.702 y-1. G. filamentosus has moderately low K value and long life span. The relation between the total length and weight of G. filamentosus was described as Log W = 1.321+2.5868 log L for males, Log W = 1.467 + 2.7227 log L for females and Log W = 1.481 + 2.7316 log L for sexes combined. The mean relative condition factor (Kn) values ranged from 0.9 to 1.14 for males, 0.89 to 1.11 for females and 0.73 to 1.08 for sexes combined. The length weight relationship and relative condition factor showed that the wellbeing of G. filamentosus were good. The morphometric measurements of various body parts were recorded. The morphometric measurements were found to be nonlinear and there is no significant difference observed between the two sexes.
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The collection of X chromosome insertions (PX) lethal lines, which was isolated from a screen for essential genes on the X chromosome, was characterized by means of cloning the insertion sites, mapping the sites within genomic DNA and determination of the associated reporter gene expresssion patterns. The established STS flanking the P element insertion sites were submitted to EMBL nucleotide databases and their in situ data together with the enhancer trap expression patterns have been deposited in the FlyView database. The characterized lines are now available to be used by the scientific community for a detailed analysis of the newly established lethal gene functions. One of the isolated genes on the X chromosome was the Drosophila gene Wnt5 (DWnt5). From two independent screens, one lethal and three homozygous viable alleles were recovered, allowing the identification of two distinct functions for DWnt5 in the fly. Observations on the developing nervous system of mutant embryos suggest that DWnt5 activity affects axon projection pattern. Elevated levels of DWNT5 activity in the midline cells of the central nervous system causes improper establishment and maintenance of the axonal pathways. Our analysis of the expression and mutant phenotype indicates that DWnt5 function in a process needed for proper organization of the nervous system. A second and novel function of DWnt5 is the control of the body size by regulation of the cell number rather than affecting the size of cells. Moreover, experimentally increased DWnt5 levels in a post-mitotic region of the eye imaginal disc causes abnormal cell cycle progression, resulting in additional ommatidia in the adult eye when compared to wild type. The increased cell number and the effects on the cell cycle after exposure to high DWNT5 levels is the result of a failure to downregulate cyclin B and therefore the unsuccessful establishment of a G1 arrest.
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Introducción: De todos los casos de cáncer en el mundo el 80% se presentan en países en vía de desarrollo siendo el cáncer de estómago o cáncer gástrico la segunda causa de muerte por cáncer en el mundo con aproximadamente 700.000 muertes cada año. En Colombia, el cáncer gástrico es la primera causa de muerte por tumores malignos en ambos sexos, aún cuando no es la primera neoplasia en frecuencia. Metodología: Estudio observacional descriptivo, de registros de defunción del DANE, Colombia 2000 a 2009. Se analizaron tasas anuales crudas y por grupos de edad, género, procedencia geográfica, estado civil, nivel educativo y área de residencia habitual estableciendo diferencias estadísticas entre las variables y sus categorías. Resultados: En el período estudiado se registraron 43759 defunciones por cáncer gástrico, con mayor frecuencia en hombres 1,5:1. Las tasas de mortalidad por cáncer gástrico ajustadas por grupos etáreos aumentan después de la quinta década de la vida. Se encontraron diferencias estadísticamente significativas en todos los años estudiados y el departamento de residencia habitual del fallecido presentando Cauca (18,11- 19) y Boyacá (14,54-1742) las tasas más altas por 100.000 habitantes. Las tasas más altas se concentran en la zona de la Cordillera de los Andes, al estandarizar por grupos etáreos el Cauca tiene una tasa de 114,98 casos por 100.000 habitantes. Conclusión: El cáncer gástrico es la neoplasia que causa más muertes en Colombia por lo cual es necesario diseñar e implementar programas de detección precoz que vayan dirigidos al control de la mortalidad.
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Introducción La mutación genética Val30Met de la proteína transtiretina (TTR) es causante de la polineuropatía amiloidótica familiar, comprometiendo en fases iniciales las fibras nerviosas pequeñas (mielinizadas Aδ y amielínicas tipo C), involucradas en funciones autonómicas, nocicepción, percepción térmica y sudoración. Los métodos neurofisiológicos convencionales, no logran detectar dichas anormalidades, retardando el inicio de tratamientos específicos para la enfermedad. Metodología El objetivo principal fue evaluar el test de cuantificación sensitiva (QST) como método de detección temprana de anormalidades de fibra pequeña, en individuos Val30Met, seguidos en el Hospital Universitario Santa María, Lisboa. Se clasificaron los pacientes en 3 grupos, según sintomatología y examen neurológico. Se analizaron los umbrales para percepción de frío, dolor con el calor y vibración en los grupos, en correlación con controles sanos. Resultados 18 registros de controles sanos y 33 de individuos con la mutación, divididos en asintomáticos (24,2%), sintomáticos con examen neurológico normal (42,4%) y sintomáticos con examen neurológico anormal (33,3%). No se encontraron diferencias entre los pacientes asintomáticos y los controles. Los umbrales para frío (p=0,042) y en el dolor intermedio con el calor (HP 5) (p=0,007) se encuentran elevados en individuos Val30Met sintomáticos con examen normal. En los pacientes sintomáticos con alteraciones al examen, también se presentaron alteraciones en el intervalo entre el inicio y el dolor intermedio con el calor (HP 5-0,5) (p=0,009). Discusión Los umbrales de frío y de percepción de dolor con el calor, permiten detectar anormalidades en personas con la mutación TTR Val30Met, sintomáticos, incluyendo aquellos sin cambios objetivos al examen neurológico.
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El present treball analitza al microscopi òptic i al microscopi electrònic de transmissió el testicle de Sus domesticus (raça Landrace - varietat anglesa) a partir de mascles reproductors porcins adults i sans. L'objectiu principal de tots els centres d'Inseminació Artificial Porcina i de les Explotacions de Selecció i Multiplicació Porcina és garantir una excel·lent qualitat espermàtica al llarg de la vida reproductiva útil d'un mascle reproductor porcí. Així doncs, un millor coneixement dels patrons estructural i ultraestructural normals del testicle permetrà diagnosticar amb facilitat quina ha estat l'estructura o funció testicular afectada quan s'observa una disminució de la qualitat del semen. Les anàlisis seminals i hormonals són certament crucials en la valoració d'aquests mascles, però, no són totalment informatives de les alteracions testiculars, ja que és necessari conèixer l'organització microscòpica. Diversos estudis sobre testicle han demostrat que els marcadors més sensibles per a l'avaluació de la funció testicular són els següents: (1) la grandària testicular, (2) el gruix i l'organització de la càpsula testicular, (3) el percentatge de túbuls seminífers i de teixit intersticial en el parènquima testicular, (4) el diàmetre dels túbuls seminífers, (5) l'alçada i la composició de cèl·lules germinals de l'epiteli seminífer, (6) el gruix i l'organització de la làmina pròpia i, (7) la morfologia i la grandària de les cèl·lules de Leydig. El primer objectiu concret del present estudi ha estat, per tant, caracteritzar tots aquests paràmetres testiculars en mascles porcins sans i adults. L'organització estructural del testicle i les mesures quantitatives utilitzades com a marcadors no mostren diferències significatives ni entres els mascles porcins (P > 0,01), ni entre el testicle dret i l'esquerre (P > 0,01). Els testicles, de 330,80 16,99 g de pes, estan envoltats per una càpsula, de 2.375,13 246,68 m de gruix, la qual es divideix en tres capes: la túnica vaginalis constitueix l'1,82 0,78 % de la càpsula i està composta per una capa mesotelial externa i una capa interna de teixit conjuntiu dens; la túnica albuginea representa el 37,31 3,27 % i és de teixit conjuntiu dens i, la túnica vasculosa constitueix el 64,24 4,40 % i és de teixit conjuntiu lax. En el parènquima testicular els túbuls seminífers i el teixit intersticial representen el 72,44 2,12 % i el 27,46 2,12 %, respectivament. Els túbuls seminífers, de 226,23 18,08 m de diàmetre, es troben fortament recargolats i empaquetats, i estan compostos per la làmina pròpia i l'epiteli seminífer. La làmina pròpia, de 4-4,5 m de gruix, està formada per la làmina basal i dues capes de cèl·lules peritubulars. L'epiteli seminífer, amb una alçada mitjana de 66,11 10,62 m, és columnar i estratificat amb cèl·lules de Sertoli i diferents generacions d'espermatogònies, espermatòcits i espermàtides. El teixit intersticial és un teixit conjuntiu lax amb abundants cèl·lules de Leydig polièdriques fortament empaquetades (ca. 15 x 12 m). El segon objectiu concret d'aquest estudi ha estat estudiar des del punt de vista morfològic i morfomètric (alçada, longitud, freqüència relativa d'aparició i durada) els estadis del cicle de l'epiteli seminífer en els mascles porcins de la raça Landrace (varietat anglesa), classificats d'acord amb el mètode de la morfologia tubular. Els estadis premeiòtics ( I, II i III) ocupen el 31,9 % del cicle espermatogènic i es caracteritzen, principalment, per la presència de cèl·lules en les fase inicials de la meiosi I. Les primeres etapes de la meiosi I no afecten els paràmetres morfomètrics de l'epiteli seminífer ja que els valors obtinguts per l'alçada de l'epiteli seminífer, la freqüència relativa, la longitud i la durada d'aquests estadis són molt variables. Els estadis meiòtics (IV i V) representen el 16,4 % del cicle espermatogènic i estan constituïts, principlament, per cèl·lules en un estat avançat de la meiosi I i /o cèl·lules en meiosi II. Les últimes fases de la meiosi I i també de la meiosi II tenen lloc ràpidament, la qual cosa resulta en una baixa freqüència relativa d'aparició i, per tant, en una baixa durada dels estadis meiòtics. Els estadis postmeiòtics (VI, VII i VIII) ocupen el 50,6 % del cicle espermatogènic. L'esdeveniment més important que té lloc en aquests estadis és la fase de maduració de l'espermiogènesi. En la fase de maduració, les espermàtides experimenten diverses modificacions morfològiques i estructurals que donen lloc, finalment, als espermatozoides. La complexitat d'aquests processos fa que els estadis postmeiòtics presentin valors més grans de freqüència relativa, longitud i durada. El tercer objectiu concret d'aquest treball ha estat descriure a nivell ultraestructural el procés d'espermiogènesi, i relacionar les transformacions que experimenten les espermàtides en fase d'elongació amb els canvis ultraestructurals que tenen lloc en les diferents cèl·lules que constitueixen el testicle (cèl·lules germinals, de Sertoli i de Leydig, principalment). L'espermiogènesi del mascle porcí de la raça Landrace (varietat anglesa) s'ha dividit en 9 passos que vénen definits per 9 tipus diferents d'espermàtides. Al llarg de l'espermiogènesi no s'observen diferències ultraestructurals significatives (P > 0,01) ni entre els mascles porcins ni entre el testicle esquerre i dret en les cèl·lules que constitueixen el testicle.
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The Perspex Machine arose from the unification of computation with geometry. We now report significant redevelopment of both a partial C compiler that generates perspex programs and of a Graphical User Interface (GUI). The compiler is constructed with standard compiler-generator tools and produces both an explicit parse tree for C and an Abstract Syntax Tree (AST) that is better suited to code generation. The GUI uses a hash table and a simpler software architecture to achieve an order of magnitude speed up in processing and, consequently, an order of magnitude increase in the number of perspexes that can be manipulated in real time (now 6,000). Two perspex-machine simulators are provided, one using trans-floating-point arithmetic and the other using transrational arithmetic. All of the software described here is available on the world wide web. The compiler generates code in the neural model of the perspex. At each branch point it uses a jumper to return control to the main fibre. This has the effect of pruning out an exponentially increasing number of branching fibres, thereby greatly increasing the efficiency of perspex programs as measured by the number of neurons required to implement an algorithm. The jumpers are placed at unit distance from the main fibre and form a geometrical structure analogous to a myelin sheath in a biological neuron. Both the perspex jumper-sheath and the biological myelin-sheath share the computational function of preventing cross-over of signals to neurons that lie close to an axon. This is an example of convergence driven by similar geometrical and computational constraints in perspex and biological neurons.
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Reducing energy use in tenanted commercial property requires a greater understanding of ‘buildings as communities’. Tenanted commercial properties represent: (1) the divergent communities that share specific buildings; and (2) the organizational communities represented by multi-site landlord and tenant companies. In any particular tenanted space the opportunity for environmental change is mediated (hindered or enabled) through the lease. This discussion draws on theoretical and practical understandings of (1) the socio-legal relationships of landlords, tenants and their advisors; (2) the real performance of engineering building services strategies to improve energy efficiency; (3) how organizational cultures affect the ability of the sector to engage with energy-efficiency strategies; and (4) the financial and economic basis of the relationship between owners and occupiers. The transformational complexity stems from: (1) the variety of commercial building stock; (2) the number of stakeholders (solicitors, investors, developers, agents, owners, tenants and facilities managers); (3) the fragmentation within the communities of practice; and (4) leasehold structures and language. An agenda is proposed for truly interdisciplinary research that brings together both the physical and the social sciences of energy use in buildings so that technological solutions are made effective by an understanding of the way that buildings are used and communities behave.
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Algorithms for computer-aided diagnosis of dementia based on structural MRI have demonstrated high performance in the literature, but are difficult to compare as different data sets and methodology were used for evaluation. In addition, it is unclear how the algorithms would perform on previously unseen data, and thus, how they would perform in clinical practice when there is no real opportunity to adapt the algorithm to the data at hand. To address these comparability, generalizability and clinical applicability issues, we organized a grand challenge that aimed to objectively compare algorithms based on a clinically representative multi-center data set. Using clinical practice as the starting point, the goal was to reproduce the clinical diagnosis. Therefore, we evaluated algorithms for multi-class classification of three diagnostic groups: patients with probable Alzheimer's disease, patients with mild cognitive impairment and healthy controls. The diagnosis based on clinical criteria was used as reference standard, as it was the best available reference despite its known limitations. For evaluation, a previously unseen test set was used consisting of 354 T1-weighted MRI scans with the diagnoses blinded. Fifteen research teams participated with a total of 29 algorithms. The algorithms were trained on a small training set (n = 30) and optionally on data from other sources (e.g., the Alzheimer's Disease Neuroimaging Initiative, the Australian Imaging Biomarkers and Lifestyle flagship study of aging). The best performing algorithm yielded an accuracy of 63.0% and an area under the receiver-operating-characteristic curve (AUC) of 78.8%. In general, the best performances were achieved using feature extraction based on voxel-based morphometry or a combination of features that included volume, cortical thickness, shape and intensity. The challenge is open for new submissions via the web-based framework: http://caddementia.grand-challenge.org.
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Dystrophin, the protein product defective in Duchenne muscular dystrophy (DMD), is present in all types of muscle and in the brain. The function of the protein is unknown and its role in the brain is unclear, although 30% of DMD patients show nonprogressive mental retardation. We have therefore studied the localisation of dystrophin in cultures of normal and DMD human fetal neurons using antibodies raised to different regions of the protein. Dystrophin immunoreactivity was demonstrated in the soma and axon hillock of normal neurons and appeared to be associated with the inner part of the cell membrane, although some intracellular staining was also observed. Positive dystrophin staining was present only in cells with fully developed neuronal features, although not all the neurons were positive. Glial cells were always negative for the antigen. Immunostaining with antibodies to the brain spectrins indicate that the dystrophin antibodies did not crossreact with these proteins. The possibility of cross-reactivity with other proteins is discussed. Studies of cells cultured from a DMD fetus also showed specific dystrophin immunostaining in neurons, although the muscle was generally negative for dystrophin. However, the localisation of dystrophin immunostaining and that of the brain spectrins and neurofilaments appeared abnormal, as did the overall morphology of the cells. This suggests that dystrophin may play a role during brain development and dystrophin deficiency results in abnormal neuronal features. This would be consistent with the nonprogressive nature of the mental retardation observed in DMD patients.
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The Namib Sand Sea in southern Africa offers an ideal location in which to consider general questions about the evolution of sand seas, about the fluxes of sand through contemporary dune fields and about the patterns of dune form that are created. This paper aims to provide a concise account of the approaches and techniques that are currently being used and will be used in the future to address these questions. The paper considers the techniques employed to investigate wind climate, the morphometry of the dunes, the internal structure of dune sediments, the age of the dunes and the potential to model dune development
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Diabetes mellitus is the most common endocrine disturbance of domestic carnivores and can cause autonomic neurological disorders, although these are still poorly understood in veterinary medicine. There is little information available on the quantitative adaptation mechanisms of the sympathetic ganglia during diabetes mellitus in domestic mammals. By combining morphometric methods and NADPH-diaphorase staining (as a possible marker for nitric oxide producing neurons), type I diabetes mellitus-related morphoquantitative changes were investigated in the celiac ganglion neurons in dogs. Twelve left celiac ganglia from adult female German shepherd dogs were examined: six ganglia were from non-diabetic and six from diabetic subjects. Consistent hypertrophy of the ganglia was noted in diabetic animals with increase of 55% in length, 53% in width, and 61.5% in thickness. The ordinary microstructure of the ganglia was modified leading to an uneven distribution of the ganglionic units and a more evident distribution of axon fascicles. In contrast to non-diabetic dogs, there was a lack of NADPH-diaphorase perikarial labelling in the celiac ganglion neurons of diabetic animals. The morphometric study showed that both the neuronal and nuclear sizes were significantly larger in diabetic dogs (1.3 and 1.39 times, respectively). The profile density and area fraction of NADPH-diaphorase-reactive celiac ganglion neurons were significantly larger (1.35 and 1.48 times, respectively) in non-diabetic dogs compared to NADPH-diaphorase-non-reactive celiac ganglion neurons in diabetic dogs. Although this study suggests that diabetic neuropathy is associated with neuronal hypertrophy, controversy remains over the possibility of ongoing neuronal loss and the functional interrelationship between them. It is unclear whether neuronal hypertrophy could be a compensation mechanism for a putative neuronal loss during the diabetes mellitus. (C) 2007 Elsevier Ltd. All rights reserved.
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We present two-dimensional stellar and gaseous kinematics of the inner 120 x 250 pc2 of the LINER/Seyfert 1 galaxy M81, from optical spectra obtained with the Gemini Multi-Object Spectrograph (GMOS) integral field spectrograph on the Gemini-North telescope at a spatial resolution of approximate to 10 pc. The stellar velocity field shows circular rotation and, overall, is very similar to the published large-scale velocity field, but deviations are observed close to the minor axis which can be attributed to stellar motions possibly associated with a nuclear bar. The stellar velocity dispersion of the bulge is 162 +/- 15 km s-1, in good agreement with previous measurements and leading to a black hole mass of M(BH) = 5.5+3.6(-2.0) x 107 M(circle dot) based on the M(BH)-Sigma relationship. The gas kinematics is dominated by non-circular motions and the subtraction of the stellar velocity field reveals blueshifts of approximate to-100 km s-1 on the far side of the galaxy and a few redshifts on the near side. These characteristics can be interpreted in terms of streaming towards the centre if the gas is in the plane. On the basis of the observed velocities and geometry of the flow, we estimate a mass inflow rate in ionized gas of approximate to 4.0 x 10-3 M(circle dot) yr-1, which is of the order of the accretion rate necessary to power the LINER nucleus of M81. We have also applied the technique of principal component analysis (PCA) to our data, which reveals the presence of a rotating nuclear gas disc within approximate to 50 pc from the nucleus and a compact outflow, approximately perpendicular to the disc. The PCA combined with the observed gas velocity field shows that the nuclear disc is being fed by gas circulating in the galaxy plane. The presence of the outflow is supported by a compact jet seen in radio observations at a similar orientation, as well as by an enhancement of the [O i]/H alpha line ratio, probably resulting from shock excitation of the circumnuclear gas by the radio jet. With these observations we are thus resolving both the feeding - via the nuclear disc and observed gas inflow, and the feedback - via the outflow, around the low-luminosity active nucleus of M81.
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This paper presents a GIS-based multicriteria flood risk assessment and mapping approach applied to coastal drainage basins where hydrological data are not available. It involves risk to different types of possible processes: coastal inundation (storm surge), river, estuarine and flash flood, either at urban or natural areas, and fords. Based on the causes of these processes, several environmental indicators were taken to build-up the risk assessment. Geoindicators include geological-geomorphologic proprieties of Quaternary sedimentary units, water table, drainage basin morphometry, coastal dynamics, beach morphodynamics and microclimatic characteristics. Bioindicators involve coastal plain and low slope native vegetation categories and two alteration states. Anthropogenic indicators encompass land use categories properties such as: type, occupation density, urban structure type and occupation consolidation degree. The selected indicators were stored within an expert Geoenvironmental Information System developed for the State of Sao Paulo Coastal Zone (SIIGAL), which attributes were mathematically classified through deterministic approaches, in order to estimate natural susceptibilities (Sn), human-induced susceptibilities (Sa), return period of rain events (Ri), potential damages (Dp) and the risk classification (R), according to the equation R=(Sn.Sa.Ri).Dp. Thematic maps were automatically processed within the SIIGAL, in which automata cells (""geoenvironmental management units"") aggregating geological-geomorphologic and land use/native vegetation categories were the units of classification. The method has been applied to the Northern Littoral of the State of Sao Paulo (Brazil) in 32 small drainage basins, demonstrating to be very useful for coastal zone public politics, civil defense programs and flood management.
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Zaprionus vittiger Coquillett is the type species of the genus Zaprionus Coquillett. However, the species is only known from five old museum specimens collected from South Africa and Malawi. It has often been confused with many other Zaprionus species, especially with Z. spinipilus Chassagnard & McEvey, a widespread species in Africa known from Madagascar, Malawi, Ethiopia and Cameroon. We have recently collected flies from the type localities of both species (South Africa and Madagascar, respectively). This has prompted us to test the taxonomic boundaries of these two nominal species using molecular (the mitochondrial COII and the nuclear Amyrel genes), chromosomal, morphological (internal and external genitalia), and reproductive isolation analyses. The results suggest Z. spinipilus to be a junior synonym to Z. vittiger.
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We see today many efforts to quantify biodiversity in different biomes. It is very important then to develop and to apply other methodologies that allow us to assess biodiversity. Here we present an example of application of three tools with this goal. We analyzed two populations of Plebeia remota from two distinct biomes that already showed several differences in morphology and behavior. Based on these differences, it has been suggested that the populations of Cunha and Prudentopolis do not represent a single species. In order to verify the existence or absence of gene flow between these two groups, we characterized the patterns of mtDNA through RFLP, the patterns of wing venation through geometric morphometry, and the cuticular hydrocarbons through gas chromatography-mass spectrometry. We used bees collected in these two locations and also from colonies which have being kept for around 9 years at Sao Paulo University. We found six different haplotypes in these specimens, of which three of them occurred exclusively in the population of Cunha and three only in the Prudentopolis population. The fact that the populations do not share haplotypes suggests no maternal gene flow between them. The two populations were differentiated by the pattern of the wing veins. They also had different mixtures of cuticle hydrocarbons. Furthermore it was shown that the colonies kept at the university did not hybridize. These two groups may constitute different species. We also show here the importance of using other methodologies than traditional taxonomy to assess and understand biodiversity, especially in bees.