1,720,979 research outputs found
Postembryonic development in pseudoscorpions: allometry in Geogarypus italicus (Pseudoscorpiones: Geogarypidae)
No full textPseudoscorpions are arachnids featuring three nymphal instars before reaching the adult age. Instars can be
mostly recognized based on the number of trichobothria which lie along the chelal axis: as the individual grows, further
trichobothria are added. The study of the post-embryonic growth based on trichobothria position has been the most widely
used approach. However, other body parts can be subjected to particular growth patterns that need to be explored to fully
understand post-embryonic development processes. Rigorous numerical approaches that allow meaningful statistical
inference within growth regressions are now available. The recently described Mediterranean species Geogarypus italicus
Gardini, Galli & Zinni, 2017 gave the authors the chance to review studies carried out in the past with the modern
statistical approach mentioned above. Results confirm the main hypothesis about the growth process of the chelal axis but
showed some differences that may be related to taxonomical aspects. Moreover, the study of body allometry during postembryonic
growth showed that not all body parts undergo the same trend from protonymphs to males, on one side, and to
females, on the other. Finally, the study of proportions between body parts through the analysis of ratios between their
linear measurements pointed out a marked sexual dimorphism of pedipalps in spite of similar sizes and proportions of
other body regions. The analysis led us to think that more interesting information could come from applying this approach
to multispecies studies
Is Acerentomon italicum Nosek, 1969 (Protura: Acerentomidae) a species complex?
No full textAcerentomon italicum Nosek, 1969 is the most abundant Protura species in Italy. Two groups of populations
characterized by the different position of a pore on tergite VII were analyzed. Specimens from Austria and from the Italian
provinces of Brescia and Bolzano (Lombardy and Alto Adige, respectively) possess a postero-sub-medial pore (psm);
in specimens from Trento (Trentino), Veneto, Friuli-Venezia Giulia and Liguria the pore is in an antero-sub-lateral (asl)
position. An integrative approach was applied to assess other characters distinguishing these populations. The lengths
of body, head, foretarsus, claw of anterior leg, foretarsal sensilla a and b were measured; in addition some ratios were
calculated: TR (length of foretarsus/length of its claw), BS (distance of sensillum t1 from base of foretarsus/distance of
t1 from foretarsus tip), length of a/foretarsus length, length of b/foretarsus length and length of a/length of b. A geometric
morphometric analysis was performed on the position of setae on tergite VII, selecting as landmarks the bases of setae
A1, A2, A3, P1, P1a, P2, P2a and P3. Nucleotide sequences COI-5P and 28S-D2-D3 of both groups were compared.
Signifi cant differences in the foretarsus and anterior claw length, in the arrangement of setae on tergite VII and in the
barcode sequences COI-5P between the “psm and asl populations” are shown to exist. Based on the results obtained, the
two groups are different, but there is not enough support to differentiate them at the species level
Wing shape variation in Orthetrum dragonflies: functional insights from citizen-science images. A geometric morphometric perspective linking shape variation and species identity.
No full textWing morphology in dragonflies reflects a complex interplay of functional constraints, ecological
adaptation, and sexual dimorphism. Using landmark-based geometric morphometrics on fore- and
hindwings of multiple Orthetrum species, we quantified interspecific and intraspecific variation, assessed
sexual shape differences, and evaluated the contribution of allometry to observed patterns. Hindwing
morphology consistently captured stronger and more structured interspecific signals than forewings, with
variation concentrated in functionally relevant regions such as the wing base and anal lobe. Sexual
dimorphism was detectable but weaker, primarily expressed in hindwings, while forewing shape appeared
constrained by stabilizing functional requirements. Allometric effects modulated but did not hide species
specific shape divergence. Notably, high-quality digital images sourced from iNaturalist have proven
suitable for large-scale morphometric analyses, enabling broad geographic and taxonomic coverage. Our
results highlight the potential of hindwing morphology as a tool for species discrimination and provide a
framework for integrating ecological, behavioral, and genetic data to understand the drivers of wing shape
evolution in Odonata
Introduction: Expanding the Cinematic Cold War or How We Learned to Cross Boundaries and Look at Bigger Pictures
No full textOmar al-Mukhtar. La cattura, il processo, l'esecuzione
No full textLa mostra ha esposto le fotografie della raccolta Giuseppe Bedendo (publico ministero del Tribunale Speciale per la difesa dello Stato della Cirenaica). Si tratta di circa ottanta stampe relative agli ultimi giorni di Omar al-Mukhtar molte delle quali inedite. La mostra era corredata da didascalie e pannelli con testi introduttivi curati da Alessandro Volterr
Acerentulus tortii sp. nov. from Greece (Protura: Acerentomidae).
No full textA new species of Protura, Acerentulus tortii sp. nov., from the island of Euboea, central Greece, is described and illustrated.
The new species belongs to the A. cunhai species group, based on a short foretarsal sensillum a not reaching seta γ3,
and sensilla b and c subequal in length. The most similar species are A. christensoni (Ewing, 1940) and A. rafalskii Szeptycki,
1979), from which A. tortii sp. nov. differs by the porotaxy of sternite III and the lengths of various foretarsal sensilla
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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