Ecosystem type drives soil eukaryotic diversity and composition in Europe

Soil eukaryotes play a crucial role in maintaining ecosystem functions and services, yet the factors driving their diversity and distribution remain poorly understood. While many studies focus on some eukaryotic groups (mostly fungi), they are limited in their spatial scale. Here, we analyzed an unprecedented amount of observational data of soil eukaryomes at continental scale (787 sites across Europe) to gain further insights into the impact of a wide range of environmental conditions (climatic and edaphic) on their community composition and structure. We found that the diversity of fungi, protists, rotifers, tardigrades, nematodes, arthropods, and annelids was predominantly shaped by ecosystem type (annual and permanent croplands, managed and unmanaged grasslands, coniferous and broadleaved woodlands), and higher diversity of fungi, protists, nematodes, arthropods, and annelids was observed in croplands than in less intensively managed systems, such as coniferous and broadleaved woodlands. Also in croplands, we found more specialized eukaryotes, while the composition between croplands was more homogeneous compared to the composition of other ecosystems. The observed high proportion of overlapping taxa between ecosystems also indicates that DNA has accumulated from previous land uses, hence mimicking the land transformations occurring in Europe in the last decades. This strong ecosystem-type influence was linked to soil properties, and particularly, soil pH was driving the richness of fungi, rotifers, and annelids, while plant-available phosphorus drove the richness of protists, tardigrades, and nematodes. Furthermore, the soil organic carbon to total nitrogen ratio crucially explained the richness of fungi, protists, nematodes, and arthropods, possibly linked to decades of agricultural inputs. Our results highlighted the importance of long-term environmental variables rather than variables measured at the time of the sampling in shaping soil eukaryotic communities, which reinforces the need to include those variables in addition to ecosystem type in future monitoring programs and conservation efforts.     

The anatomical characters related to the brooding behavior of two Antarctic species of <Emphasis Type="Italic">Mysella</Emphasis> Angas, 1877 (Bivalvia,Galeommatoidea, Lasaeidae), with direct and indirect evidences of ovoviviparity

Brood protection is a common feature of marine bivalves from higher latitudes. In this study the pallial organs of the Antarctic bivalves, Mysella charcoti (Lamy, 1906) and M. narchii Passos & Domaneschi, 2006 were investigated with respect to anatomical characters related to brooding. Both species are simultaneous hermaphrodites and their eggs contain a large amount of yolk. The number of broods ranges from 16 to 30 in M. narchii and 7–27 in M. charcoti, and ovoviviparity was observed for both. Their ctenidia differ in structure, those of M. charcoti being simpler. In M. narchii there is a large elasticity of the tissue of the marginal food grooves of ctenidia, and cilia are much more abundant on the ctenidial abfrontal surface and on the visceral mass epithelium than in M. charcoti. Anatomical characters of M. charcoti can be considered derived when compared to those of M. narchii. In conclusion, detailed anatomical characters related to brooding may be useful in future systematic studies of Antarctic Bivalvia.     

Global 5-methylcytosine and physiological changes are triggers of indirect somatic embryogenesis in Coffea canephora

Protoplasma - Indirect somatic embryogenesis (ISE) establishment for Coffea species started in the 1970s. Since then, intraspecific variations in the morphogenic pathway have been reported, even in...     

8-Mercaptoguanine-based inhibitors of Mycobacterium tuberculosis dihydroneopterin aldolase: synthesis,in vitro inhibition and docking studies

The dihydroneopterin aldolase (DHNA, EC 4.1.2.25) activity of FolB protein is required for the conversion of 7,8-dihydroneopterin (DHNP) to 6-hydroxymethyl-7,8-dihydropterin (HP) and glycolaldehyde (GA) in the folate pathway. FolB protein from Mycobacterium tuberculosis (MtFolB) is essential for bacilli survival and represents an important molecular target for drug development. S8-functionalized 8-mercaptoguanine derivatives were synthesised and evaluated for inhibitory activity against MtFolB. The compounds showed IC₅₀ values in the submicromolar range. The inhibition mode and inhibition constants were determined for compounds that exhibited the strongest inhibition. Additionally, molecular docking analyses were performed to suggest enzyme-inhibitor interactions and ligand conformations. To the best of our knowledge, this study describes the first class of MtFolB inhibitors.     

Southern Lapwing Vanellus chilensis cooperative helpers at nests are older siblings

Cooperative breeding is rare in shorebirds, and when found it is thought to be due to polygamous mating (cooperative polygamy). Here we describe the social structure of cooperatively breeding groups in Southern Lapwing Vanellus chilensis and test the prediction that offspring sex ratio is skewed towards the sex that helps. The social groups consisted of a breeding pair with one or two young (mostly males, 68%) from the previous breeding season, and offspring sex ratio was not skewed. Cooperative breeding in the Southern Lapwing is not the consequence of cooperative polygamy, but rather groups were formed by a mated pair and some of their offspring from previous nests as helpers.     

Electronic structure and magnetic coupling of two dinuclear trigonal bipyramidal cobalt(II) complexes

The EPR spectra of zinc-doped (bis(N-methylsalicylaldiminato)cobalt(II), (Zn, Co) SALMe, which was found to be dinuclear, and of zinc-doped bis(N,N-bis(2-(diethylamino)ethyl)-2-hydroxyethylamino-O)dicobalt(II)diperchlorate, (Zn, Co)n₃o, were recorded at liquid helium temperature and X-band frequency.The polycrystalline powder spectra of (Zn, Co)SALMe were interpreted within an effective S = 1/2 spin hamiltonian formalism with g₁ = 1.8, g₂ = 2.7, g₃ = 6.2, while those of (Zn, Co)n₃o showed only one band at G= 6.9. The single crystal spectra for the latter yielded g₁ = 0.31(4), g₂ = 0.84(4), g₃ = 6.86(2). The electronic structure of the complexes was calculated using the AOM, and the lowest Kramers doublet for CoSALMe was found to be ±1/2 while a ±3/2 doublet was found for Con₃o. The temperature dependence of the magnetic susceptibility of CoSALMe was measured between 295 and 4.2 K. The data were fitted with two different methods which either took into account or neglected the zero-field splitting of single ions. The coupling was found to be antiferromagnetic with J = 9.8(2) cm^-1 (J is defined through the hamiltonian = JS₁·S₂). The extent of the magnetic interaction between the metal ions for both the complexes was discussed on the basis of a structural analysis.     

Influence of resin cement thickness and temperature variation on mechanical behavior of dental ceramic fragment restoration

To evaluate the stress behavior of ceramic fragment restoration, varying the thickness of the cement layer and intraoral temperature variation. A solid model of a upper lateral incisor was obtained and a defect at enamel distal/incisal edge was restored with a ceramic fragment. Based on this initial model, 4 different models (M) were built: M1 – absence of cement layer (CL) (0?μm of thickness); M2 – CL with an uniform thickness of 50?μm; M3 – CL with 50?μm at the margin of ceramics and 100?μm in the inner area far from margins; M4 – CL with 50?μm at the margin of ceramics and 200?μm in the inner area far from margins. The environment temperature changed from 5?°C to 50?°C in 4 increments. The finite element analysis was performed. Increase the cement layer thickness generated higher stress levels on ceramic surface in all temperatures, as well as on cement interface. In general hot temperature was the worst scenario for ceramic fragments integrity, since tensile and compressive stress were more intense. The maximum principal stress on ceramic fragment was found 90?MPa for M4 at 50?°C, followed for M3 (87?Mpa). For CL, the peak of stress was found for M3 at 5?°C (47?MPa). Is it possible to conclude that thick resin cement layer contribute to higher stress concentration on ceramic fragment, and extremely hot temperatures increase the risk of structural failure, since both ceramic and \cl are exposed to higher compressive and tensile stresses.     

Extraocular Photoreception and Circadian Entrainment in Nonmammalian Vertebrates

In mammals both the regulation of circadian rhythms and photoperiodic responses depend exclusively upon photic information provided by the lateral eyes; however, nonmammalian vertebrates can also rely on multiple extraocular photoreceptors to perform the same tasks. Extraocular photoreceptors include deep brain photoreceptors located in several distinct brain sites and the pineal complex, involving intracranial (pineal and parapineal) and extracranial (frontal organ and parietal eye) components. This review updates the research field of the most recent acquisitions concerning the roles of extraocular photoreceptors on circadian physiology and behavior, particularly photic entrainment and sun compass orientation.