Syntaxonomy of the Robinia pseudoacacia communities in the central peri-adriatic sector of the Italian peninsula

This study presents the results of a floristic vegetational study on Robinia pseudoacacia neoformation forests in the peri-Adriatic sector of central Italy. This has allowed the characterization of these coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These currently represent the southernmost syntaxa of the Robinietea class described for the Italian peninsula, and the first syntaxonomic contribution of this class in Europe for the Mediterranean biogeographical region. We propose here the new alliance Lauro nobilis–Robinion pseudoacaciae of the order Chelidonio–Robinietalia pseudoacaciae and class Robinietea, with two new associations: Melisso altissimae–Robinietum pseudoacaciae and Rubio peregrinae–Robinietum pseudoacaciae. The new alliance Lauro nobilis–Robinion pseudoacaciae (typus: Melisso altissimae–Robinietum pseudoacaciae) brings together neoformation forests and pre-forest dominated by R. pseudoacacia in those territories with a Mediterranean macroclimate of the peri-Adriatic sector of central Italy. The optimum is found for the alluvial plain and low-slope morphologies, on soils that are moist and rich in organic matter and in areas with anthropic disturbance. On the basis of comparisons with the European context, the alliance Bryonio–Robinion described for the temperate territories of northern Italy is here validated.     

Temperature and rainfall interact to control carbon cycling in tropical forests

Tropical forests dominate global terrestrial carbon (C) exchange, and recent droughts in the Amazon Basin have contributed to short‐term declines in terrestrial carbon dioxide uptake and storage. However, the effects of longer‐term climate variability on tropical forest carbon dynamics are still not well understood. We synthesised field data from more than 150 tropical forest sites to explore how climate regulates tropical forest aboveground net primary productivity (ANPP) and organic matter decomposition, and combined those data with two existing databases to explore climate – C relationships globally. While previous analyses have focused on the effects of either temperature or rainfall on ANPP, our results highlight the importance of interactions between temperature and rainfall on the C cycle. In cool forests (< 20 °C), high rainfall slowed rates of C cycling, but in warm tropical forests (> 20 °C) it consistently enhanced both ANPP and decomposition. At the global scale, our analysis showed an increase in ANPP with rainfall in relatively warm sites, inconsistent with declines in ANPP with rainfall reported previously. Overall, our results alter our understanding of climate – C cycle relationships, with high precipitation accelerating rates of C exchange with the atmosphere in the most productive biome on earth.     

Specific protein changes contribute to the differential muscle mass loss during ageing

In the skeletal muscle, the ageing process is characterized by a loss of muscle mass and strength, coupled with a decline of mitochondrial function and a decrease of satellite cells. This profile is more pronounced in hindlimb than in forelimb muscles, both in humans and in rodents. Utilizing light and electron microscopy, myosin heavy chain isoform distribution, proteomic analysis by 2D‐DIGE, MALDI‐TOF MS and quantitative immunoblotting, this study analyzes the protein levels and the nuclear localization of specific molecules, which can contribute to a preferential muscle loss. Our results identify the molecular changes in the hindlimb (gastrocnemius) and forelimb (triceps) muscles during ageing in rats (3‐ and 22‐month‐old). Specifically, the oxidative metabolism contributes to tissue homeostasis in triceps, whereas respiratory chain disruption and oxidative‐stress‐induced damage imbalance the homeostasis in gastrocnemius muscle. High levels of dihydrolipoyllysine‐residue acetyltransferase (Dlat) and ATP synthase subunit alpha (Atp5a1) are detected in triceps and gastrocnemius, respectively. Interestingly, in triceps, both molecules are increased in the nucleus in aged rats and are associated to an increased protein acetylation and myoglobin availability. Furthermore, autophagy is retained in triceps whereas an enhanced fusion, decrement of mitophagy and of regenerative potential is observed in aged gastrocnemius muscle.     

DNAH6 and Its Interactions with PCD Genes in Heterotaxy and Primary Ciliary Dyskinesia

Heterotaxy, a birth defect involving left-right patterning defects, and primary ciliary dyskinesia (PCD), a sinopulmonary disease with dyskinetic/immotile cilia in the airway are seemingly disparate diseases. However, they have an overlapping genetic etiology involving mutations in cilia genes, a reflection of the common requirement for motile cilia in left-right patterning and airway clearance. While PCD is a monogenic recessive disorder, heterotaxy has a more complex, largely non-monogenic etiology. In this study, we show mutations in the novel dynein gene DNAH6 can cause heterotaxy and ciliary dysfunction similar to PCD. We provide the first evidence that trans-heterozygous interactions between DNAH6 and other PCD genes potentially can cause heterotaxy. DNAH6 was initially identified as a candidate heterotaxy/PCD gene by filtering exome-sequencing data from 25 heterotaxy patients stratified by whether they have airway motile cilia defects. dnah6 morpholino knockdown in zebrafish disrupted motile cilia in Kupffer’s vesicle required for left-right patterning and caused heterotaxy with abnormal cardiac/gut looping. Similarly DNAH6 shRNA knockdown disrupted motile cilia in human and mouse respiratory epithelia. Notably a heterotaxy patient harboring heterozygous DNAH6 mutation was identified to also carry a rare heterozygous PCD-causing DNAI1 mutation, suggesting a DNAH6/DNAI1 trans-heterozygous interaction. Furthermore, sequencing of 149 additional heterotaxy patients showed 5 of 6 patients with heterozygous DNAH6 mutations also had heterozygous mutations in DNAH5 or other PCD genes. We functionally assayed for DNAH6/DNAH5 and DNAH6/DNAI1 trans-heterozygous interactions using subthreshold double-morpholino knockdown in zebrafish and showed this caused heterotaxy. Similarly, subthreshold siRNA knockdown of Dnah6 in heterozygous Dnah5 or Dnai1 mutant mouse respiratory epithelia disrupted motile cilia function. Together, these findings support an oligogenic disease model with broad relevance for further interrogating the genetic etiology of human ciliopathies.     

Heliotherapy for Neonatal Hyperbilirubinemia in Southwest,Nigeria: A Baseline Pre-Intervention Study

Background

A novel filtered-sunlight phototherapy (FSPT) device has been demonstrated to be safe and efficacious for treating infants with neonatal jaundice in resource-constrained tropical settings. We set out to provide baseline data for evaluating the clinical impact of this device in a referral pediatric hospital.

Methods

We reviewed the medical records of infants admitted for neonatal hyperbilirubinemia in an inner-city Children’s Hospital in Lagos, between January 2012 and December 2014 to determine the pattern, treatment and outcomes during the pre-intervention period. Factors associated with adverse outcomes were identified through multivariable logistic regression.

Results

Of the 5,229 neonatal admissions over the period, a total of 1,153 (22.1%) were admitted for neonatal hyperbilirubinemia. Complete records for 1,118 infants were available for analysis. The incidence of acute bilirubin encephalopathy (ABE) and exchange transfusion (ET) were 17.0% (95% CI: 14.9%–19.3%) and 31.5% (95% CI: 28.8%–34.3%) respectively. A total of 61 (5.5%, 95% CI: 4.3%–6.9%) of the jaundiced infants died. Weight on admission, peak total serum bilirubin (TSB), sepsis and exposure to hemolytic products were predictive of ABE, while age on admission, peak TSB, ABO incompatibility and ABE were predictive of ET. Rhesus incompatibility, asphyxia, exposure to hemolytic substances and ABE were associated with elevated mortality risk, while ET was a protective factor. Lack of routine irradiance monitoring and steady energy supply were frequent challenges for conventional blue-light phototherapy.

Conclusions

Severe hyperbilirubinemia is associated with high rates of ABE and ET in this setting, and remains a significant contributor to neonatal admissions and mortality. To be impactful, FSPT, complemented with improved diagnostic facilities, should effectively curtail jaundice-related adverse outcomes in this and comparable settings.     

Schistosomiasis in Lake Malawi: Relationship of Fish and Intermediate Host Density to Prevalence of Human Infection

Prior to 1985, the open waters of Lake Malawi were free from schistosome transmission. Over the past decades, however, the prevalence of urinary schistosomiasis has increased dramatically in the southern part of the lake. We found the prevalence of human schistosomiasis in school-aged children to be negatively correlated with the density of molluscivorous fishes. Specifically, the increased infection rate in southern Lake Malawi between 1978 and 1991 is coincident with the reduction in numbers of snail-eating fishes. During 2003, we determined the relative abundance of molluscivorous fishes and snail density at 18 sites throughout the lake and schistosome infection in school-aged children living in selected lakeshore communities of Lake Malawi. At the 18 sites sampled in 2003, we found that snail abundance decreased with an increase in abundance of snail-eating fishes. Furthermore, the 2003 samples showed that the abundance of snail-eating fishes increased and there was a reduction in schistosomiasis in school-aged children in Chembe Village. We believe that we will not observe a return to the 1978 infection rates until these fishes continue to increase and inhabit shallower waters.     

Transmembrane topology of FRO2, a ferric chelate reductase from Arabidopsis thaliana

Iron uptake in Arabidopsis thaliana is mediated by ferric chelate reductase FRO2, a transmembrane protein belonging to the flavocytochrome b family. There is no high resolution structural information available for any member of this family. We have determined the transmembrane topology of FRO2 experimentally using the alkaline phosphatase fusion method. The resulting topology is different from that obtained by theoretical predictions and contains 8 transmembrane helices, 4 of which build up the highly conserved core of the protein. This core is present in the entire flavocytochrome b family. The large water soluble domain of FRO2, which contains NADPH, FAD and oxidoreductase sequence motifs, was located on the inside of the membrane.Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at This work was supported by grants from the Swedish Research Council (VR) to S. Al-Karadaghi and Hans Hebert.     

Reproductive Consequences of Clonal Growth in Stenocereus eruca, a Rare Clonal Cactus of the Sonoran Desert

Stenocereus eruca is a prostrated, self-incompatible cactus endemic to the Sonoran Desert that regenerates primarily through clonal propagation. Clonal growth is expected to affect mate availability by influencing the number and spatial distribution of mating types. In this paper we examine the role of clonal growth on female fecundity through a series of pollination experiments in a population of S. eruca. We set up a pollen supplementation experiment using five distance treatments with pollen collected at 1, 10, 100, 1000 and 25000 m from receptor flowers during the years 2001 and 2002 and evaluated genetic sifmilarities between pairs of receptor-donor ramets through RAPD markers. Our data on fruit set, number of seeds/fruit, germination and overall fecundity revealed that S. eruca show a significant reduction in female fecundity when pollination occurs between ramets located at short distances (1 and 10 m), while genetic data showed high levels of similarity at those distances. The reduction in female fecundity is apparently a consequence of geitonogamy and inbreeding depression. Our data suggest that clonal growth and geitonogamy are likely to be partially responsible for the low levels of sexual reproduction and seedling recruitment observed in populations of S. eruca. Co-ordinating editor: H. Kudoh     

Searching the conformational complexity and binding properties of HDAC6 through docking and molecular dynamic simulations

Histone deacetylases (HDACs) are a family of proteins involved in the deacetylation of histones and other non-histones substrates. HDAC6 belongs to class II and shares similar biological functions with others of its class. Nevertheless, its three-dimensional structure that involves the catalytic site remains unknown for exploring the ligand recognition properties. Therefore, in this contribution, homology modeling, 100-ns-long Molecular Dynamics (MD) simulation and docking calculations were combined to explore the conformational complexity and binding properties of the catalytic domain 2 from HDAC6 (DD2-HDAC6), for which activity and affinity toward five different ligands have been reported. Clustering analysis allowed identifying the most populated conformers present during the MD simulation, which were used as starting models to perform docking calculations with five DD2-HDAC6 inhibitors: Cay10603 (CAY), Rocilinostat (RCT), Tubastatin A (TBA), Tubacin (TBC), and Nexturastat (NXT), and then were also submitted to 100-ns-long MD simulations. Docking calculations revealed that the five inhibitors bind at the DD2-HDAC6 binding site with the lowest binding free energy, the same binding mode is maintained along the 100-ns-long MD simulations. Overall, our results provide structural information about the molecular flexibility of apo and holo DD2-HDAC6 states as well as insight of the map of interactions between DD2-HDAC6 and five well-known DD2-HDAC6 inhibitors allowing structural details to guide the drug design. Finally, we highlight the importance of combining different theoretical approaches to provide suitable structural models for structure-based drug design.