Activity and space patterns of Pyrenean desman (Galemys pyrenaicus) suggest non-aggressive and non-territorial behaviour

The Pyrenean desman is considered a flagship species for biodiversity and evolution. However, its scientific knowledge is still under development and currently on debate, particularly in relation to its behavioural ecology and social organization. Based on the previous hypothesis of individual desmans being solitary and territorial, activity and space patterns were considered to be arranged to avoid conspecifics. However, recent insights into the species’ social behaviour revealed non-interspecific avoidance. With this study, we provide novel insights into the activity and space patterns of the desman, and their relation to its social behaviour. A total of 30 individuals were trapped, 18 of which provided informative radiotracking data to study (1) activity behaviour, (2) the proportion of the home range utilized and the distances travelled, and (3) the dominant movement directionality. Activity and space use patterns were affected by daylight and seasonality, but not by sex, age or number of other conspecifics sharing the home range. In contrast to the previous observations, individuals did not show a pattern of directionality in their movements. Noticeably, we observed encounters between individuals without evidence of aggressive behaviour. Our results suggest that desmans do not alter their activity or their spatial behaviour to avoid encounters with conspecifics, as previously suggested. These novel findings provide more evidence of a social structure and organization with social interactions and non-aggressive behaviour. This is of relevance for management actions and for the conservation of this endemic mammal

Surface quality related to machining parameters in 3D-printed PETG components

Fused Deposition Modeling (FDM) finds extensive application across various fields due to its cost-effectiveness and user-friendly nature. However, it does come with certain limitations, including challenges in achieving high surface quality, precise dimensional tolerance, and the characteristic anisotropic mechanical properties it exhibits. The aim of this paper is to investigate the machinability of 3D-printed PETG and analyze the roughness and burr formation that occurs as a result. A Design of Experiments (DoE) was developed with three factors: rotational speed, feed rate, and depth of cut. Each factor had different levels: rotational speed at 3000, 5500, and 8000 rpm; feed rate at 400, 600, and 800 mm/min; and depth of cut at 0.2, 0.4, 0.6, and 0.8 mm. The machinability was evaluated based on two response parameters: roughness (Sa), determined on the milled surface, and burr height, measured using a profilometer on both sides of the milled surface. The findings indicate that milling parameters strongly affect roughness and burr formation. However, the optimal conditions for minimizing roughness and burr formation are not coincident. The results were also compared to the machinability of PLA machined under similar conditions

Bonding of similar AA3105 aluminum alloy by accumulative roll bonding process

Accumulative roll-bonding (ARB) is a novel plastic straining process aimed at bonding of similar and dissimilar metal combinations. Moreover, it is used recently to produce ultrafine grain materials and metal matrix reinforced composites to enhance mechanical, electrical, and corrosion resistance properties. This work presents an experimental study of roll bonding and accumulative roll bonding of similar AA3105 aluminum alloy at 300°C with a final thickness of 1.2 mm, focusing especially on bond strength evaluation and layers continuities. Tensile tests and three-points bending were performed to mechanical characterize the produced sheets in the various steps and based on the number of the cycles. The maximum strength was reached after 3 ARB cycles. After 4 cycles, the bonding interfaces have a uniform distribution through the sheet thickness, it is possible to distinguish only the interface formed in the last pass in the fracture surface, and no significant enhancement in strength was observed. Starting from 2 ARB cycles, micro-cracks were observed at the outer surface for bending angles greater than 90 deg, and at 180 deg all ARBed samples except A1 were failed

Surface Quality Related to Face Milling Parameters in 3D Printed Carbon Fiber-Reinforced PETG

Three-dimensional printing technology holds significant potential for enhancing the flexibility and cost-efficiency of producing carbon fiber-reinforced polymer composites (CFRPs). However, it faces limitations such as challenges in achieving high surface qualityand precise dimensional accuracy and managing the distinctive anisotropic mechanical properties that it demonstrates. This study aims to explore the machinability of 3D printed PETG infused with 20% short carbon fiber and to assess the resulting surface roughness and burr formation. Employing a Design of Experiments (DoE) approach, three factors were considered: rotational speed, feed rate, and depth of cut. These factors were tested at varying levels—rotational speeds of 3000, 5500, and 8000 rpm; feed rates of 400, 600, and 800 mm/min; and depth of cut values of 0.2, 0.4, 0.6, and 0.8 mm. The evaluation of machinability relied on two key response parameters: surface roughness (Sa) determined from the milled surface and burr height measured on both sides using a roughness meter. The findings revealed a significant influence of milling parameters on both roughness and burr formation. However, the ideal conditions for minimizing roughness and reducing burr formation did not align. Furthermore, a comparative analysis was conducted between these results and the machinability of PETG under similar conditions

El complex Euphorbia esula-E. virgata (Euphorbiaceae) al nord-est de la península Ibèrica: precisions corològiques, ecològiques i taxonòmiques

The recent discovery in the north-east of the Iberian Peninsula (southern and central Catalonia) of three populations belonging to the Euphorbia esula–E. virgata complex (Euphorbiaceae) prompted us to conduct a macro- and micromorphological study to ascertain their taxonomic identity. Only two previous records of plants from this complex existed in the area and these were gathered in 1908/1909 (previously identified as E. esula subsp. saratoi) and in 1930 (E. esula s. l.). Our results indicate that all the material examined (both recent and old samples) can be attributed to E. virgata, a taxon whose main distribution area lies in eastern Europe, and whose southwestern distribution limit lies in northeastern Iberian Peninsula. The macromorphological characteristics vary somewhat between populations and some individual plants bear a strong resemblance to forms that are usually referred to E. ×pseudovirgata, a supposed hybrid of E. virgata and E. esula. It is not possible, however, to confirm the presence of this hybrid in the region without further studies. After this study, E. esula subsp. esula should be excluded from Catalonia, Valencia and Aragon. The present-day populations we attribute to E. virgata are highly localized but dense. They are found in herbaceous habitats with clear anthropic influence (abandoned fields and the edges of roads and tracks), on deep, fairly dry soils. These habitats are similar to those typical of E. virgata in eastern and central Europe. It is likely that the populations are temporal and indeed in two of the three recent localities it has been confirmed that they date from after 2005. Current data suggest that this is a non-indigenous species, but in view of the fact that it was detected a century ago, the possibility that it is a rare indigenous species with itinerant populations cannot be ruled out.El hallazgo reciente de tres poblaciones del complejo Euphorbia esula-E. virgata (Euphorbiaceae) en el nordeste de la Península Ibérica (centro y sur de Cataluña) nos ha inducido a realizar un estudio macro y micromorfológico para establecer su identidad taxonómica. En esta zona tan sólo existían dos datos previos de plantas de este complejo, correspondientes a recolecciones de los años 1908/1909 (previamente identificadas como E. esula subsp. saratoi) y 1930 (E. esula s. l.). Según nuestros resultados, todo el material examinado (recolecciones recientes y antiguas) se puede atribuir a E. virgata, un taxon de área principal en el este de Europa, que encuentra en el nordeste de la Península Ibérica su límite suroccidental de distribución. Los caracteres macromorfológicos presentan un cierto grado de variación interpoblacional, y en algún caso los individuos se parecen mucho a las formas que suelen denominarse E. ×pseudovirgata, supuestamente híbridas entre E. virgata y E. esula, pero no es posible confirmar la presencia regional de este híbrido sin la realización de estudios complementarios. Con los resultados de este estudio, debe excluirse la presencia de E. esula subsp. esula de Cataluña, Valencia y Aragón. Las poblaciones actuales de E. virgata, muy localizadas pero densas, se sitúan en hábitats herbáceos con clara influencia antrópica (campos abandonados y bordes de carreteras y caminos), en suelos profundos bastante secos; estos hábitats son similares a los típicos de E. virgata en Europa oriental y central. Aparentemente se trata de poblaciones de carácter temporal, y en dos de las tres localidades recientes se ha confirmado que se han establecido con posterioridad a 2005. Los datos actuales sugieren que puede tratarse de una especie alóctona, pero considerando que se detectó ya hace un siglo, no se puede excluir que sea una autóctona rara con poblaciones itinerantes. [ct] La troballa recent de tres poblacions del complex Euphorbia esula-E. virgata (Euphorbiaceae) al nord-est de la península Ibèrica (centre i sud de Catalunya) ens ha induït a realitzar-ne un estudi macro i micromorfològic, per tal d’establir la seva identitat taxonòmica. En aquesta zona només existien dues dades prèvies de plantes d’aquest complex, corresponents a recol·leccions dels anys 1908/1909 (prèviament identificades com a E. esula subsp. saratoi) i 1930 (E. esula s. l.). Segons els nostres resultats, tot el material examinat (recol·leccions recents i antigues) es pot atribuir a E. virgata, un tàxon d’àrea principal a l’est d’Europa, que troba al nord-est de la península Ibèrica el seu límit sud-occidental de distribució. Els caràcters macromorfològics presenten un grau limitat de variabilitat interpoblacional, i en algun cas s’assemblen molt a les formes que solen anomenar-se E. ×pseudovirgata, suposadament híbrides entre E. virgata i E. esula, però sense estudis addicionals no és possible confirmar la presència regional d’aquest híbrid. Després d’aquest estudi cal excloure la presència d’E. esula subsp. esula de Catalunya, el Pais Valencià i l’Aragó. Les poblacions actuals d’E. virgata, molt localitzades però denses, es fan en hàbitats herbacis amb influència antròpica clara (camps abandonats i marges de carreteres i camins), en sòls profunds força secs; aquests hàbitats són similars als típics d’E. virgata a l’Europa central i oriental. Aparentment es tracta de poblacions de caràcter temporal, i en dues de les tres localitats s’ha confirmat un establiment posterior a 2005. Les dades actuals suggereixen que pot tractar-se d’una planta al·lòctona, però considerant que ja va ser detectada fa un segle, tampoc no es pot excloure que sigui una autòctona rara i amb poblacions itinerants

Effect of Selective Z-Pinning on the Static and Fatigue Strength of Step Joints between Composite Adherends

The z-pinning reinforcement technique, which involves inserting thin pins through the body of a laminate, has proven highly effective in enhancing the strength of various composite joint configurations. This investigation aims to explore the enhancements achievable through selective z-pinning at very low pin contents on both the static and fatigue performance of composite joints. Single-step joints between carbon/epoxy adherends were reinforced using steel pins arranged in two, three, or four rows of pins parallel to the edges of the overlap, resulting in pin contents ranging from 0.2% to 0.4%. Joint panels were manufactured through co-curing, and coupons were extracted from the panels for static and fatigue tensile testing. The experimental tests show that z-pinning improves the static strength (by about 15%) and extends the fatigue lives of the joints. The ultimate failure of both unpinned and pinned joints is due to the unstable propagation of a crack at the bond line. The superior performances of pinned joints are mainly due to the bridging tractions imposed between the crack faces by z-pins, which delay the growth of the debonding crack. The enhancements in static and fatigue strength achieved by z-pinning were essentially independent of the number of pin rows, and the pins positioned near the joint edges were found to play a dominant role in controlling the structural performance of pinned joints

Examining the variability of neurocognitive functioning in individuals at clinical high risk for psychosis: a meta-analysis

This study aims to meta-analytically characterize the presence and magnitude of within-group variability across neurocognitive functioning in young people at Clinical High-Risk for psychosis (CHR-P) and comparison groups. Multistep, PRISMA/MOOSE-compliant systematic review (PROSPERO-CRD42020192826) of the Web of Science database, Cochrane Central Register of Reviews and Ovid/PsycINFO and trial registries up to July 1, 2020. The risk of bias was assessed using a modified version of the NOS for cohort and cross-sectional studies. Original studies reporting neurocognitive functioning in individuals at CHR-P compared to healthy controls (HC) or first-episode psychosis (FEP) patients were included. The primary outcome was the random-effect meta-analytic variability ratios (VR). Secondary outcomes included the coefficient of variation ratios (CVR). Seventy-eight studies were included, relating to 5162 CHR-P individuals, 2865 HC and 486 FEP. The CHR-P group demonstrated higher variability compared to HC (in descending order of magnitude) in visual memory (VR: 1.41, 95% CI 1.02-1.94), executive functioning (VR: 1.31, 95% CI 1.18-1.45), verbal learning (VR: 1.29, 95% CI 1.15-1.45), premorbid IQ (VR: 1.27, 95% CI 1.09-1.49), processing speed (VR: 1.26, 95% CI 1.07-1.48), visual learning (VR: 1.20, 95% CI 1.07-1.34), and reasoning and problem solving (VR: 1.17, 95% CI 1.03-1.34). In the CVR analyses the variability in CHR-P population remains in the previous neurocognitive domains and emerged in attention/vigilance, working memory, social cognition, and visuospatial ability. The CHR-P group transitioning to psychosis showed greater VR in executive functioning compared to those not developing psychosis and compared to FEP groups. Clinical high risk for psychosis subjects shows increased variability in neurocognitive performance compared to HC. The main limitation of this study is the validity of the VR and CVR as an index of variability which has received debate. This finding should be explored by further individual-participant data research and support precision medicine approaches