Phorophyte size and soil profiles differentially correlate with community structure among hemiepiphytes and nomadic vines

Tropical non-self-supporting plants such as hemiepiphytes and nomadic vines are model organisms for disentangling biotic and environmental correlates which influence their occupancy patterns. We inventoried >4000 individuals from >3000 trees ranging from 1 to 200 cm diameter at breast height (DBH) in a northeastern Amazonian upland forest to address how tree (phorophyte) size, edaphic factors and recruitment strategy influence occupancy, diversity, and compositional patterns of two vascular non-self-supporting plant functional groups. Hemiepiphytes germinate on phorophytes prior to establishing soil connections, whereas nomadic vines initiate their life cycle on the forest floor and subsequently climb phorophytes for crown access, abandoning roots replaced by adventitious connections which may reach the ground. Our results show that larger phorophytes (≥30 cm DBH) supported more species for both hemiepiphytes and nomadic vines. However, nomadic vines' occupancy probabilities saturated faster at smaller stem sizes than that of hemiepiphytes indicating differential preferences for stem sizes among the two functional groups. For smaller phorophytes (<30 cm DBH), soil correlations were stronger with nomadic vines than hemiepiphytes, whereas no significant differences were detected among functional groups in relation to edaphic factors for larger (≥ 30 cm DBH) ones. Finally, a small core group of species showed disproportionately greater abundances among large phorophytes suggesting that autogenic processes differentially promote survivability. Such interactions among phorophyte size and edaphic factors may result from the contrasting ecological requirements of hemiepiphytes and nomadic vines at the recruitment stage, demonstrating the necessity for elaborate demographic-based studies to better understand these complex plant–plant interactions. Abstract in Spanish is available with online material     

Humid acid influence on the growth and copper tolerance of chlorella sp.

The authors describe and discuss experiments carried out withChlorella sp. in which the effect of humic acid on its growth was studied. Also the coupled effect of humic acid and tolerance to cupric ions was demonstrated. Some ecological implication are discussed.     

Cercarial chaetotaxy of Euparyphium albuferensis Esteban et al., 1997 (Trematoda: Echinostomatidae), with a review of some genera of the Echinostomatinae

Euparyphium albuferensis Esteban et al., 1997 (Trematoda: Echinostomatidae) is a parasite of the mollusc Gyraulus chinensis (D.) (Gastropoda: Planorbidae) and the mammals Rattus spp. in a nature park near Valencia, Spain. In the present work, the cercarial chaetotaxy is fully determined for specimens emitted by naturally infected G. chinensis. Of particular importance are the following sensillary arrangements: 5 CIV DL, 3 CIV CIV D at the dorso-cephalic level and 0 UV and 22–26 UD in the tail. Evidence is presented to the effect that these sensillary clusters are characteristic of the genus Euparyphium and allow an easy diagnosis, unlike in the case of the adult worms where there are sometimes few or no differences between Echinoparyphium and Echinostoma. A table synthesises the main data on the cercarial sensilla of Euparyphium spp. and the closely related genera Echinoparyphium, Echinostoma, Hypoderaeum, Moliniella, Neoacanthoparyphium, Paryphostomum and Isthmiophora. This shows clear variations in their respective numbers, from 3–5 in CIV DL, 2–4 in CIV D, 0–15 in UV and 19 to 57 in UD, according to the genus. These clusters appear adequate to identify, at the cercarial stage, the principal genera of the Echinostomatinae.     

Reisolamento di una rara specie di Lievito: Trigonopsis variabilis Schachner

Zusammenfassung Trigonopsis variabilis, bisher erst einmal isoliert (1929), wurde in einem Traubenmost aus dem Weinbaugebiet des Staates S. Paulo, Brasilien, wieder aufgefunden. Es wird sein morphologisches und physiologisches Verhalten unter verschiedenen Kulturbedingungen beschrieben.     

Isolation and characterisation of polymorphic microsatellite markers for the endangered ferreous limpet <Emphasis Type="Italic">Patella ferruginea</Emphasis> (Gastropoda,Patellidae)

The limpet Patella ferruginea is one of the most endangered marine invertebrates on western Mediterranean rocky shores. We have isolated and characterised 11 polymorphic microsatellites markers to provide new tools to investigate genetic structure and gather information necessary for the proper management of this severely threatened species. The number of alleles per locus ranged from 2 to 16 (mean; Na = 8.37) with an average observed heterozygosity of 0.64 (He = 0.66). The levels of polymorphism uncovered at these loci suggest that they should be useful for population genetic studies, parentage analysis and assessment of connectivity among protected areas. None of the pairwaise comparisons among loci showed significant linkage disequilibrium after sequential Bonferroni correction. All but one locus (Pf-31IF1) conformed to HW equilibrium. Further investigation revealed that departures at Pf-31IF1 were not caused by null alleles. Results from cross-species amplifications suggest that some of these loci may also be useful for Patella tenuis (two loci) P. ulyssiponensis (one locus) and P. piperata (three loci).     

AAV-mediated inhibition of ULK1 promotes axonal regeneration in the central nervous system in vitro and in vivo

Axonal damage is an early step in traumatic and neurodegenerative disorders of the central nervous system (CNS). Damaged axons are not able to regenerate sufficiently in the adult mammalian CNS, leading to permanent neurological deficits. Recently, we showed that inhibition of the autophagic protein ULK1 promotes neuroprotection in different models of neurodegeneration. Moreover, we demonstrated previously that axonal protection improves regeneration of lesioned axons. However, whether axonal protection mediated by ULK1 inhibition could also improve axonal regeneration is unknown. Here, we used an adeno-associated viral (AAV) vector to express a dominant-negative form of ULK1 (AAV.ULK1.DN) and investigated its effects on axonal regeneration in the CNS. We show that AAV.ULK1.DN fosters axonal regeneration and enhances neurite outgrowth in vitro. In addition, AAV.ULK1.DN increases neuronal survival and enhances axonal regeneration after optic nerve lesion, and promotes long-term axonal protection after spinal cord injury (SCI) in vivo. Interestingly, AAV.ULK1.DN also increases serotonergic and dopaminergic axon sprouting after SCI. Mechanistically, AAV.ULK1.DN leads to increased ERK1 activation and reduced expression of RhoA and ROCK2. Our findings outline ULK1 as a key regulator of axonal degeneration and regeneration, and define ULK1 as a promising target to promote neuroprotection and regeneration in the CNS.Subject terms: Cell death in the nervous system, Neurodegeneration, Spinal cord injury     

Size and crown shape predict reproductive maturity of Carapa guianensis in upland and floodplain forests in the northeastern Amazon

Comprehending the size distribution within a population and grasping its connection to tree maturation (onset of reproductive phase) is pivotal for formulating sustainable management strategies and conserving numerous tree species. The objective of this study was to compare the structure and probability of fruit production of Carapa guianensis in two types of forest (varzea, or floodplain, vs. terra firme, or upland) in the northeastern Amazon, Brazil. The study was conducted in four permanent plots of 300 × 300 m (two for each type of forest). All individuals ≥10 cm in diameter at breast height (DBH) were mapped and measured for DBH, height, and canopy characteristics (shape and position), and liana infestation. Sixty-seven trees were inventoried in the upland forest and 297 in the floodplain forest. The trees were larger in the upland (33.36 ± 1.84 cm) than in the floodplain (21.92 ± 1.5 cm) and more than half (56%) of the upland trees and more than two thirds (67%) of floodplain trees were reproductive. The minimum diameter for fruit production in the floodplain (10.2 cm of DBH) was more than two times smaller than in the upland (25.5 cm of DBH). The probability of fruit production of a tree of the same size was twice as high in the floodplain compared with the upland, and trees with rounded canopies had a higher probability of fruit production in the upland. Our results showed that the probability of fruit production can be modeled with variables of tree size and canopy shape, and that intrinsic factors of the forests influence the reproductive maturity of C. guianensis which presents greater precocity and productive potential of seeds in the estuarine floodplain forest of the Amazon River.     

Ultrastructure of the ovary of Dermatobia hominis (Diptera: Cuterebridae). II. Origin of the tunica propria in ovarioles

Ovaries up to the 8th day pupae of Dermatobia hominis were studied by transmission electron microscopy. Ovarioles were recognized in ovaries of 4-day old pre-pupae, surrounded by a thin tunica propria of acellular fibrillar material similar in structure to the internal portion of the external tunica of the ovary. There is continuity of the tunica propria and the ovarian tunica, indicating that the former structure originates from the tunica externa. In 5 to 7-day pupae the interstitial somatic cells from the apical region of the ovary, close to the ovarioles, show delicate filamentous material inside of their rough endoplasmic reticulum cisternae; similar material is seem among these cells. Our observations suggest that interstitial somatic cells do not originate the tunica propria but contribute to its final composition.