Centro Científico Tecnológico Mar del Plata

Abstract Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (∼50% of these regions have multiple independent associations); these include 24 novel SLE regions ( P <5 × 10 −8 ), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.

The marine areas of South America (SA) include almost 30,000 km of coastline and encompass three different oceanic domains--the Caribbean, the Pacific, and the Atlantic--ranging in latitude from 12∘N to 55∘S. The 10 countries that border these coasts have different research capabilities and taxonomic traditions that affect taxonomic knowledge. This paper analyzes the status of knowledge of marine biodiversity in five subregions along the Atlantic and Pacific coasts of South America (SA): the Tropical East Pacific, the Humboldt Current,the Patagonian Shelf, the Brazilian Shelves, and the Tropical West Atlantic, and it provides a review of ecosystem threats and regional marine conservation strategies. South American marine biodiversity is least well known in the tropical subregions (with the exception of Costa Rica and Panama). Differences in total biodiversity were observed between the Atlantic and Pacific oceans at the same latitude. In the north of the continent, the Tropical East Pacific is richer in species than the Tropical West Atlantic, however, when standardized by coastal length, there is very little difference among them. In the south, the Humboldt Current system is much richer than the Patagonian Shelf. An analysis of endemism shows that 75% of the species are reported within only one of the SA regions, while about 22% of the species of SA are not reported elsewhere in the world. National and regional initiatives focusing on new exploration, especially to unknown areas and ecosystems, as well as collaboration among countries are fundamental to achieving the goal of completing inventories of species diversity and distribution.These inventories will allow accurate interpretation of the biogeography of its two oceanic coasts and latitudinal trends,and will also provide relevant information for science based policies.

Nitric oxide (NO) signaling regulates various physiological processes in both animals and plants. In animals, NO synthesis is mainly catalyzed by NO synthase (NOS) enzymes. Although NOS-like activities that are sensitive to mammalian NOS inhibitors have been detected in plant extracts, few bona fide plant NOS enzymes have been identified. We searched the data set produced by the 1000 Plants (1KP) international consortium for the presence of transcripts encoding NOS-like proteins in over 1000 species of land plants and algae. We also searched for genes encoding NOS-like enzymes in 24 publicly available algal genomes. We identified no typical NOS sequences in 1087 sequenced transcriptomes of land plants. In contrast, we identified NOS-like sequences in 15 of the 265 algal species analyzed. Even if the presence of NOS enzymes assembled from multipolypeptides in plants cannot be conclusively discarded, the emerging data suggest that, instead of generating NO with evolutionarily conserved NOS enzymes, land plants have evolved finely regulated nitrate assimilation and reduction processes to synthesize NO through a mechanism different than that in animals.

Much progress has been made in the past few decades in understanding the sources, transport, fate, and biological effects of contaminants of emerging concern (CECs) in aquatic ecosystems. Despite these advancements, significant obstacles still prevent comprehensive assessments of the environmental risks associated with the presence of CECs. Many of these obstacles center around the extrapolation of effects of single chemicals observed in the laboratory or effects found in individual organisms or species in the field to impacts of multiple stressors on aquatic food webs. In the present review, we identify 5 challenges that must be addressed to promote studies of CECs from singular exposure events to multispecies aquatic food web interactions. There needs to be: 1) more detailed information on the complexity of mixtures of CECs in the aquatic environment, 2) a greater understanding of the sublethal effects of CECs on a wide range of aquatic organisms, 3) an ascertaining of the biological consequences of variable duration CEC exposures within and across generations in aquatic species, 4) a linkage of multiple stressors with CEC exposure in aquatic systems, and 5) a documenting of the trophic consequences of CEC exposure across aquatic food webs. We examine the current literature to show how these challenges can be addressed to fill knowledge gaps. Environ Toxicol Chem 2019;38:46-60. © 2018 SETAC.

[1] This work provides an initial overview of climate features and their related hydrological impacts during the recent extreme droughts (1995, 1998, 2005 and 2010) in the upper Solimões River (western Amazon), using comprehensive in situ discharge and rainfall datasets. The droughts are generally associated with positive SST anomalies in the tropical North Atlantic and weak trade winds and water vapor transport toward the upper Solimões, which, in association with increased subsidence over central and southern Amazon, explain the lack of rainfall and very low discharge values. But in 1998, toward the end of the 1997–98 El Niño event, the drought is more likely related to an anomalous divergence of water vapor in the western Amazon that is characteristic of a warm event in the Pacific. During the austral spring and winter of 2010, the most severe drought since the seventies has been registered in the upper Solimões. Its intensity and its length, when compared to the 2005 drought, can be explained by the addition of an El Niño in austral summer and a very warm episode in the Atlantic in boreal spring and summer. As in 2005, the lack of water in 2010 was more important in the southern tropical tributaries of the upper Solimões than in the northern ones.

Igor Rudan and colleagues report the results of their consensus building exercise that identified health research priorities to help reduce child mortality from pneumonia.

Historically, the recommended time between placement and functional loading of machined-surface dental implants has been 3 months for the mandible and 6 months for the maxilla. However, such recommendations are a result of evaluating randomly chosen healing times during the initial phase of implant development and are based on the subsequent clinical outcome of either implant integration or mobility. In recent years, histologic and experimental studies have shown that specifically designed micro-topographic implant surfaces can result in increased bone-to-implant contact at earlier healing times than obtained with machined-surface implants. Histologic and clinical studies investigating early and immediate implant loading support the premise that implants can be placed into function earlier than previously recommended. With the development of specifically designed implant surfaces and the utilization of time-saving surgical (one-stage surgical protocol) and prosthetic (implant position indexing) techniques, patients are now being restored and returning to function sooner than previously thought possible. The purpose of this multicenter clinical investigation is to evaluate the efficacy of loading Osseotite dental implants (3i-Implant Innovations Inc., Palm Beach Gardens, Florida) at 2 months and to determine the effect of early loading on implant performance and survival. A total of 429 Osseotite implants were placed in 155 patients (87 females and 68 males; mean age 54.0 +/- 13.7 yr), at 10 study centers, and subsequently loaded 2.1 +/- 0.7 months following placement. A single-stage surgical protocol was followed, with implants indexed immediately or impressed 4 to 6 weeks following placement. Patient restorative treatments included placement of 83 single-implant provisional restorations and 129 splinted, two-, three-, and four-implant supported maxillary and mandibular provisional restorations. The mean time from prosthetic loading to the most recent follow-up evaluation was 10 +/- 1.3 months. Seven of the 429 implants did not integrate; of these, six were identified prior to loading and one was identified 1 month after loading. The cumulative implant survival rate was 98.5% at 12.6 months. The cumulative post-loading implant survival rate was 99.8% at 10.5 months. The preliminary results of this clinical investigation suggest that successful functional loading of the Osseotite dental implant is possible at 2 months following noncomplicated implant placement.

The shape of epoxy–acid based vitrimers can be changed either temporarily or permanently by selecting the appropriate thermal treatment.

Due to their social behaviour, honey bees can be infected by a wide range of pathogens including the microsporidia Nosema ceranae and the bacteria Paenibacillus larvae. The use of probiotics as food additives for the control or prevention of infectious diseases is a widely used approach to improve human and animal health. In this work, we generated a mixture of four Lactobacillus kunkeei strains isolated from the gut microbial community of bees, and evaluated its potential beneficial effect on larvae and adult bees. Its administration in controlled laboratory models was safe for larvae and bees; it did not affect the expression of immune-related genes and it was able to decrease the mortality associated to P. larvae infection in larvae and the counts of N. ceranae spores from adult honey bees. These promising results suggest that this beneficial microorganism's mixture may be an attractive strategy to improve bee health. Field studies are being carried out to evaluate its effect in naturally infected colonies.

of basic fibroblast growth factor. These results show that the ionic dissolution products released from the bioactive glass 45S5.2B stimulate angiogenesis in vivo. The effects observed are attributed to the presence the ionic dissolution products, which contained 160 ± 10 µM borate.

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = .05 to .005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance testing altogether. There are alternatives that address study design and sample size much more directly than significance testing does; but none of the statistical tools should be taken as the new magic method giving clear-cut mechanical answers. Inference should not be based on single studies at all, but on cumulative evidence from multiple independent studies. When evaluating the strength of the evidence, we should consider, for example, auxiliary assumptions, the strength of the experimental design, and implications for applications. To boil all this down to a binary decision based on a p-value threshold of .05, .01, .005, or anything else, is not acceptable.

On the basis of their thermal preferences, salmon introduced in South America can distribute over the whole Southern Patagonian Shelf Ecosystem (SPSE). Stable isotope (δ 13 C andδ 15 N) data show that the SPSE is dominated by zooplanktivorous species (15 of 37), and its community is distributed over six trophic levels (TL), with salmonids occupying levels 4.2 to 4.9. A dual isotope mixing model was used to estimate diet proportions of adult salmonids (validated with stomach content analyses) and showed that chinook salmon (TL 4.9) and brown trout (TL 4.7) feed largely on sprats (96% and 79% predicted by the model) and were clustered together with intermediate size fish and cephalopod predators (TL 4.6‐5), a diet similar to that in their native ranges (North Pacific and North Atlantic Oceans). Adult anadromous rainbow trout clustered together with zooplanktivorous species (TL 3.2‐4.4), and the model predicted a diet dominated by planktonic crustaceans (55%), very different from the diet dominated by fish and squids characteristic of adult steelhead in the North Pacific Ocean. Diet predictions based on stable isotopes for Chinook salmon were indistinguishable from direct assessments of stomach contents of fish captured by bottom trawlers and overlapped widely with the diet of Magellanic penguins. The lack of reports on captures of anadromous rainbow trout by bottom trawlers suggests that this species has a shallower distribution. Stable isotope data for rainbow trout are very similar to those of rockhopper penguins, which feed on planktonic crustaceans, fish larvae, and juveniles.

In a previous publication, we performed a phenotypic characterization of Arabidopsis auxin receptor mutants grown under oxidative and salt stresses. In particular, the double mutant for TIR1 and AFB2 receptors, tir1 afb2 displayed increased tolerance against salinity measured as germination rate, root elongation and chlorophyll content. Here, it is reported that salicylic acid (SA)-treated tir1 afb2 mutant shows enhanced transcript level of a pathogenesis related gene, PR1. In addition, SA-mediated repression of auxin signaling was also demonstrated. All these findings allow us to suggest that down-regulation of auxin signaling may be a common mechanism within the plant adaptative response against both biotic and abiotic stresses.

Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species' relative abundance will more rapidly advance our understanding of invasions.

A representative section of the Holocene alluvial record of the southern Pampas (Argentina) com prises a sequence of clastic sediments, a diatomite and two palaeosols. Detailed macro- and micromorphological descriptions provide the basis for the reconstruction of its pedosedimentary history. Combining the pedosedi mentary reconstruction with palaeoecological data allows a detailed overview of alluvial landscape development and associated palaeoenvironmental change in the region during the Holocene. The early-Holocene shift from a subhumid dry to humid climate was marked initially by a diminution in clastic sedimentation, the development of the Puesto Callejón Viejo Soil and then re-establishment of fluvial aggradation with a dominance of bioclastic sedimentation. Loess inputs increased during the mid-Holocene as the climate reverted to subhumid dry, and temporary subaerial exposure of the sediments led to the formation of the Puesto Berrondo Soil. More variable environmental conditions followed with natural fluvial aggradation ceasing in the late Holocene, though aeolian sedimentation has continued until the present day. The resultant surface accretionary soil has been modified by recent alluvial inputs from flood events linked to agricultural disturbance in adjacent catchments.

The urbanization process grows continuously over pristine areas creating new habitats and situations for birds. In this study we analize the abundance and distribution of bird species along an urban gradient in Mar del Plata City during the breeding season. We recorded birds in transects in downtown, suburban residential areas and periurban residential areas. The proportion of trees and shrubs and of lawn increased in less urbanized areas. Richness, diversity and abundance of birds were higher at suburban and periurban sites, and were significantly correlated with the proportion of trees and shrubs, and of lawn. Most guilds followed the same trend, except omnivorous birds, which were similarly abundant along the urban gradient. Similarity was higher between bird communities in suburban and periurban sites. Of the 15 species that were statistically analized, exotic species like Columba livia and Passer domesticus were more abundant in the most urbanized areas. Other 8 species were equally abundant in suburban and periurban areas. Milvago chimango, Turdus rufiventris and Agelaioides badius were more abundant in the periurban areas.

This study investigated the level of seabird mortality caused by the domestic trawl fleet (freshies) for hake (among other less important targets) operating in waters off central Patagonia (37–48°S), analyzing the effect of environmental and operational variability on the level of seabird interactions. With a total of 135 vessels, the fleet is one of the largest in Argentina. Specifically tasked seabird observers were placed onboard trawlers during the summer and winter seasons of the years 2006 and 2007. The type and number of seabird interactions (i.e. contacts with fishing gear) were recorded during shooting and hauling operations, covering 72 days of observation and 328 trawls. Black-browed albatrosses, white-chinned petrels Procellaria aequinoctialis, southern giant petrels Marconectes giganteus and southern royal albatrosses Diomedea epomophora were the most abundant species interacting with trawlers. Confirmed mortalities of black-browed and southern royal albatrosses were the result of collisions and entanglement with the warp cable while birds were scavenging. The estimated total mortality rate was 0.017 birds h−1 and 0.105 birds per vessel per day. The intensity of interactions (in terms of the number of contacts per unit time) was largely explained by the distribution of the fishing effort. Seasonality and the incidence of discards were the strongest factors explaining the occurrence of seabird interactions. The total annual mortality in the trawl fleet under investigation was roughly estimated to be from several hundred to over a thousand albatrosses. However, these figures should be considered preliminary due to the limited spatial and temporal coverage of data and the fact that estimations were based on a low number of observed mortalities. The implementation of a strategic discard management may significantly reduce the number of seabird mortalities from collisions with warp cables or improve the effectiveness of other complementary mitigation methods. Urgent implementation of mitigation measures is needed in this fleet to reduce the mortality of albatrosses and petrels along the Patagonian shelf.

Periodic swarms or blooms of gelatinous macrozooplankton have a negative effect on many human activities such as tourism, fisheries, and industry, but for several reasons (sampling procedures, underestimation of their real abundance, etc.), they have often been neglected in the local literature. The high spatial resolution exercise of the South-western Atlantic anchovy Engraulis anchoita Recruitment Project (SARP) was therefore also suitable for estimating standing stocks of jelly macrozooplankton, attempting to establish particular environmental patterns exerting control on the spatial distribution of these facultative carnivorous predators in coastal frontal environments. These studies were carried out through a sampling programme on board the German R/V Meteor in three different systems, convergence and divergent, in the South-western Atlantic Ocean: Region A (42°S) on the Argentine shelf, characterised by tidal mixing fronts; Region B (36°S), the freshwater outflow from Río de la Plata; and Region C (28°S), under upwelling events in subtropical waters on the Brazilian shelf. In general, a dominance of gelatinous macrozooplankton, compared with the other fraction of macrozooplankton and micronekton was observed. Mean standing stock of the gelatinous zooplankton was always greater than 50% of organic carbon (org. C) in every section analysed. The lobate ctenophore Mnemiopsis leidyi dominated the zooplankton biomass in Region A, Argentina. It represented 60% of total org. C and was more abundant at the stratified zone of the front. Ctenophores were also dominant in Region B, Río de la Plata, where the related species Mnemiopsis mccradyi and the cydippid ctenophore Pleurobrachia pileus comprised 81% of total org. C. Mnemiopsis was most common in areas of vertical thermal and saline stratification, while Pleurobrachia was dominant in the less stratified areas. Gelatinous zooplankton was also the principal component of the macrozooplankton biomass in Region C, Brazil. The hydromedusae Rhacostoma atlantica and Olindias sambaquiensis dominated both the total and gelatinous biomass (68% and 7% of total org. C), being always more abundant under lower thermal stratification. It was found that, both in convergent and divergent local systems, gelatinous plankton tended to aggregate in areas where the presence of isolines outcropping to the surface (associated with production processes) was observed. These results are discussed in the context of existing hypotheses regarding ecosystem production and food webs.

Abstract Quorum sensing ( QS ) is a bacterial communication mechanism that depends on population density. QS inhibitory activity of four bioactive agents and two essential oils was evaluated using the bacteria model Chromobacterium violaceum . On the other hand, antimicrobial activity was tested using two foodborne pathogens, Listeria monocytogenes and Escherichia coli . Agents were able to inhibit the violacein production, being tea tree and rosemary more effective than propolis and pollen, and resveratrol more effective than pomegranate. Tea tree and rosemary essential oils, applied at 0.5 μ L / mL , reduced violacein production by more than 80%. In order to evaluate whether the inhibition of violacein production owed to the microbial growth reduction or acylated homoserine lactone inhibition, the antimicrobial activity was analyzed using C. violaceum as indicator. None of the tested agents showed antimicrobial activity at the minimal QS inhibitory concentration. Agents showed varying degrees of antibacterial activity against pathogens. Tea tree and rosemary resulted more effective than the others. These essential oils showed bacteriostatic effect on pathogen counts at low concentrations (0.5–1 μ L / mL ). When they were applied at concentrations higher than 2 μ L / mL , bactericidal effect was observed against E. coli and L. monocytogenes . These findings strongly suggest that these agents have potential to be good preservatives because of anti‐ QS capacity and antimicrobial properties. Practical Applications Food spoilage is a complex process, and excessive amounts of foods are lost due to microbial spoilage even with modern day preservation techniques. Another problem related to public health is the contamination of foods with human pathogen microorganisms. Quorum sensing ( QS ) is a cell‐to‐cell communication mechanism by which bacterial population measures its cell density. Because many important animal and plant pathogens use QS to regulate virulence, the interruption of bacteria QS have broad applicability for biological control of disease‐causing organisms. It is considered a good strategy to reduce or prevent spoilage reaction in foods. In this work, we investigated antimicrobial activity against foodborne pathogens and anti‐ QS activity (using Chromobacterium violaceum ) of some bioactive extracts and essential oils. The results obtained from this study indicate that agents tested could potentially be used as natural preservatives to prolong shelf life and ensure safety of foods.

BACKGROUND: Cerebrovascular disease may cause "vascular depression" (VaD). Calcium channel-blockers are presumed treatments for cerebrovascular disease and might be expected to improve depression and prevent recurrence. OBJECTIVE: To examine the efficacy and tolerability of the use of nimodipine as an augmentation of fluoxetine in the treatment of VaD. DESIGN: A double-blind, randomized clinical trial in which 101 patients with VaD (Alexopoulos criteria) were treated with fluoxetine at standard doses. Patients were randomized to placebo (n=51) or nimodipine (n=50). Treatment outcomes were assessed using the Hamilton Depression Rating Scale (HDRS) regularly up to 8 months after treatment initiation. RESULTS: Depression was reduced in 63% of patients, but those whose treatment was enhanced with nimodipine had greater improvements overall by repeated measures analysis of covariance (ANCOVA) (F(1.80) = 9.76, p=0.001). In addition, a greater proportion of patients treated with fluoxetine-nimodipine (54% vs. 27%) exhibited full remission (chi2(d.f. 1)= 7.3, p = 0.006), with the number needed to treat (NNT) equal to 4 (95% CI 2-12). Of those experiencing full remission in the first 61 days, fewer patients on fluoxetine-nimodipine (3.7%) developed recurrence of major depression as compared to those on fluoxetine alone (35.7%) (chi2(d.f. 1) = 7.56, p = 0.006), NNT 3 (95% CI 2-9). Side-effects were noted in 33.3% of patients in the control group and 48% of the experimental group (chi2(d.f. 1) = 2.25, p = 0.133). CONCLUSIONS: In treating VaD, augmentation of fluoxetine with nimodipine led to better treatment results and lower rates of recurrence. These findings support the argument that augmentation of antidepressant therapy might be helpful in the treatment of cerebrovascular disease, which is involved in the pathogenesis of this type of depression.