Molecular phylogeny of the Notostraca

We used a combined analysis of one nuclear (28S rDNA) and three mitochondrial markers (COI, 12S rDNA, 16S rDNA) to infer the molecular phylogeny of the Notostraca, represented by samples from the six continents that are inhabited by this group of branchiopod crustaceans. Our results confirm the monophyly of both extant notostracan genera Triops and Lepidurus with good support in model based and maximum parsimony analyses. We used branchiopod fossils as a calibration to infer divergence times among notostracan lineages and accounted for rate heterogeneity among lineages by applying relaxed-clock models. Our divergence date estimates indicate an initial diversification into the genera Triops and Lepidurus in the Mesozoic, most likely at a minimum age of 152.3–233.5 Ma, i.e., in the Triassic or Jurassic. Implications for the interpretation of fossils and the evolution of notostracan morphology are discussed. We further use the divergence date estimates to formulate a biogeographic hypothesis that explains distributions of extant lineages predominantly by overland dispersal routes. We identified an additional hitherto unrecognised highly diverged lineage within Lepidurus apus lubbocki and three additional previously unknown major lineages within Triops. Within T. granarius we found deep differentiation, with representatives distributed among three major phylogenetic lineages. One of these major lineages comprises T. cancriformis, the T. mauritanicus species group and two hitherto unrecognised T. granarius lineages. Samples that were morphologically identified as T. granarius diverged from the most basal nodes within this major lineage, and divergence dates suggested an approximate age of 23.7– 49.6 Ma for T. cancriformis, indicating the need for a taxonomic revision of Triassic and Permian fossils that are currently attributed to the extant T. cancriformis.We thus elevate T. cancriformis minor to full species status as Triops minor Trusheim, 1938 and include in this species the additional Upper Triassic samples that were attributed to T. cancriformis. We further elevate T. cancriformis permiensis to full species status as Triops permiensis Gand et al., 1997

The efficacy of time-based short-course acyclovir therapy in treatment of post-herpetic pain

Introduction: Various treatments have been used to manage post-herpetic neuralgia (PHN). Safe and effective therapies to prevent PHN are needed. Methodology: A clinical trial involving 152 patients diagnosed with acute herpes Zoster (HZ) was conducted to determine whether short-course acyclovir therapy (800 mg five times a day for four days) can alleviate HZ-associated pain and prevent post-herpetic neuralgia (PHN). The patients were divided into two groups: Group 1 had a rash with a duration of less than 72 hours and Group 2 had a rash with a duration of more than 72 hours. To assess PHN, the patients categorized and assessed the severity of their symptoms using a four-point verbal rating scale (VRS). Results: By the fourth week, 134 out of 152 patients (88.2) had complete pain response (CPR). Of these, 68 patients (89.5) were from Group 1 and 66 from Group 2 (86.8). After four weeks, the mean VRS scores had changed significantly in both groups compared to the scores at the beginning of study (p = 0.001), but there was no difference between the two groups (0.88 ± 0.66 Vs. 0.94 ± 0.72; p = 0.66) After three months no differences were observed in the treatment results between the two groups (0.51 ± 0.13 Vs.0.54 ± 0.19; p = 0.77). Conclusion: Short-course acyclovir therapy is an effective treatment for zoster and its efficacy in patients with a rash duration of more than 72 hours is similar to that in patients with rash duration of less than 72 hours. © 2010 Rasi et al

Defining the importance of landscape metrics for large branchiopod biodiversity and conservation: the case of the Iberian Peninsula and Balearic Islands

The deficiency in the distributional data of invertebrate taxa is one of the major impediments acting on the bias towards the low awareness of its conservation status. The present study sets a basic framework to understand the large branchiopods distribution in the Iberian Peninsula and Balearic Islands. Since the extensive surveys performed in the late 1980s, no more studies existed updating the information for the whole studied area. The present study fills the gap, gathering together all available information on large branchiopods distribution since 1995, and analysing the effect of human population density and several landscape characteristics on their distribution, taking into consideration different spatial scales (100 m, 1 km and 10 km). In overall, 28 large branchiopod taxa (17 anostracans, 7 notostracans and 4 spinicaudatans) are known to occur in the area. Approximately 30% of the sites hosted multiple species, with a maximum of 6 species. Significant positive co-occurring species pairs were found clustered together, forming 4 different associations of large branchiopod species. In general, species clustered in the same group showed similar responses to analysed landscape characteristics, usually showing a better fit at higher spatial scales.Brazilian Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq [401045/2014-5]Spanish Ministry of Education, Culture and Sport [FPU014/06783]info:eu-repo/semantics/publishedVersio

Electronic supplementary material that includes 2 supplementary figures. from <i>Gilsonicaris</i> from the Lower Devonian Hunsrück slate is a eunicid annelid and not the oldest crown anostracan crustacean

The Lower Devonian (Lower Emsian, −400 Myr) roof slates of the Hunsrück in southeastern Germany have delivered a highly diverse and exceptionally preserved marine fauna that provides a unique snapshot into the anatomy and ecology of a wide range of Palaeozoic animals. Several of the described taxa, however, remain enigmatic in their affinity, at least until new pyritized features hidden under the surface of the slate are revealed using X-ray radiography or micro-computed tomography (µCT). Here, we redescribe such an enigmatic fossil, the putative anostracan crustacean Gilsonicaris rhenanus Van Straelen, 1943. Using µCT scanning, we unveil unprecedented details of its anatomy, including a ventral oral opening and four pairs of recalcitrant jaw elements. These jaws are morphologically consistent with the scolecodonts of eunicidan polychaetes, which along with the gross anatomy of the body and head unambiguously identifies G. rhenanus as a polychaete rather than an arthropod. While this discovery firmly discards the Early Devonian record of crown anostracans in the fossil record, it adds a new record of eunicidan soft tissues, which are surprisingly rare considering the abundant microfossil record of scolecodonts

Adaptation to thermally variable environments: capacity for acclimation of thermal limit and heat shock response in the shrimp Palaemonetes varians

In the context of climate change, there is a sustained interest in understanding better the functional mechanisms by which marine ectotherms maintain their physiological scope and define their ability to cope with thermal changes in their environment. Here, we present evidence that the variable shrimp Palaemonetes varians shows genuine acclimation capacities of both the thermal limit (CTmax) and the heat shock response (hsp70 induction temperature). During cold acclimation to 10°C, the time lag to retune the stress gene expression to the current environmental temperature proved to exceed one week, thereby highlighting the importance of long term experiments in evaluating the species’ acclimation capacities. Cold and warm-acclimated specimens of P. varians can mobilise the heat shock response (HSR) at temperatures above those experienced in nature, which suggests that the species is potentially capable of expanding its upper thermal range. The shrimp also survived acute heat shock well above its thermal limit without subsequent induction of the HSR, which is discussed with regard to thermal adaptations required for life in highly variable environments

Hardening in relation with microstructure evolution of high purity α-titanium deformed under monotonic and cyclic simple shear loadings at room temperature

International audienceThe aim of this paper is to gain understanding of the quasi-static, large strain deformation behavior at room-temperature of high-purity α-Ti with an initial split-basal texture. Simple shear tests were conducted along different directions in order to quantify the material's anisotropy and hardening evolution for different strain paths such as monotonic, Bauschinger, and cyclic loadings. The stress–strain curves indicate that the material displays strong anisotropy in the flow behavior. In order to capture the link between microstructure evolution (occurrence of twinning, grain size evolution, etc.) and the macroscopic response, a thoroughly detailed multi-scale characterization using scanning electron microscope (SEM) observations and electron backscattered diffraction (EBSD) analysis was also conducted. Specifically, EBSD analyses indicate that the twin activity and grain fragmentation are responsible for the observed difference between the macroscopic hardening rates corresponding to different directions and loading paths