High resolution geochemical mapping in the Mociços mine (Ossa-Morena Zone, Portugal). Contributes from machine learning methods

The Mociços mine was exploited for copper in the early twentieth century. A recent soil geochemistry campaign with portable X-ray fluorescence equipment permited to map the surroundings of this ancient mine with high resolution. The analysis of the results using machine learning methods, namely, principal component analysis, hierarchical and k-mean clustering, and the mapping of the observations, allows a better understanding of the geochemical behavior of the elements. The principal component analysis and the k-means method have comparable results and allow to define the zone of mineralization and the outcropping of a dyke of acid rocks. The hierarchical agglomeration method allows to group the mineralized zones with the mine waste sites. Using the spatial mapping of the clusters it was possible to identify the regions marked by the geochemical behaviour of copper and zinc as well as to find relationships between the mineralized vein and outcropping acid rocks in the region

Ecological trend on demersal community in the Southern Grand Banks (NAFO Div. 3NO) from the Spanish Surveys: 2002-2011

Some ecological indices were calculated from the data obtained in the research surveys conducted by Spain in NAFO divisions 3NO between the years 2002 and 2011. These indices were calculated for individual populations (intrinsic population rate of growth and mean length) and for all the community (ABC curves, indices about faunal diversity, proportion of non-commercial species, mean length in community and size spectra). We use the data of twenty five species caught in the survey along the years, included Northern shrimp (Pandalus borealis). The data of Northern shrimp, capelin (Mallotus villosus) and Northern sand lance (Ammodytes dubius) have a great influence in the value of the indices, as their abundance is very high in relation to their contribution to the biomass. The indices present a general stable pattern with a slight improvement in recent years. After two decades of moratorium, yellowtail flounder (Limanda ferruginea) seems to be recovered and other important commercial species as Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides) begin to recover in the South of the Grand Banks

Persistence and Variation on the Groundfish Assemblages on Flemish Cap (NAFO Divisions 3M): 2004-2013

Data from the EU (Spain-Portugal) bottom trawl surveys in the Division 3M of the NAFO Regulatory Area (2004-2013) were analyzed to examine patterns on this zone of groundfish assemblage structure and diversity in relation to depth. 1699 hauls between 129 and 1460 m in depth were carried out. We focused on the 29 most abundant species, which made up 87.5% of the catch in terms of biomass. Assemblage structure was strongly correlated with depth. For the most part, changes in assemblages seem to be fairly continuous, although there were more abrupt changes at 600 m. Three main assemblages were identified. A shallow assemblage was found in the shelf. Assemblage I (Shallow) comprises the strata with depths lesser than 250 m and include American plaice (Hippoglossoides platessoides), witch flounder (Glyptocephalus cynoglossus) and Atlantic cod (Gadus morhua). Assemblage II (Intermediate) includes the strata with depths between 251 and 600 m and comprises Acadian redfish (Sebastes fasciatus), Arctic eelpout (Lycodes reticulates), thorny skate (Amblyraja radiata), longfin hake (Phycis chesteri), deepwater redfish (Sebastes mentella), spinytail skate (Bathyraja spinicauda) and Northern wolffish (Anarichas denticulatus). Three species are present in the two first assemblages: Atlantic wolffish (Anarichas lupus), golden redfish (Sebastes marinus) and spotted wolffish (Anarichas minor). Assemblage III (Deep) contains the depth strata greater than 601 m. Marlin-spike (Nezumia bairdii), scaly dragonfish (Stomias boa), Greenland halibut (Reinhardtius hippoglossoides), sloane’s viperfish (Chaulonius sloani), black dogfish (Centroscyllium fabricii), Snubnosed spiny eel (Notacanthus chemitzii), roughhead grenadier (Macrourus berglax), roundnose grenadier (Coryphaenoides rupestris), blue antimora (Antimora rostrata), threadfin rockling (Gaidropsarus ensis), bean’s sawtoothed eel (Serrivomer beanii), Northern cutthroat eel (Syphanobranchus kaupii), lanternfish (Lampanyctus sp), vahls’s eelpout (Lycodes vahlii), Arctic skate (Amblyraja hyperborea) and Demon catshark (Apristurus sp) formed Assemblage III. Despite dramatic changes in biomass and abundance of the species in the area, the boundaries and composition of the assemblages seem to be similar to the period before the collapse. Extending depth range to 1460 m, no another boundaries were found. Although some changes were evident, the main ones were replacements of the dominant species in several assemblages and bathymetric range extension of distribution of some species. Acadian redfish and golden redfish appear to be the dominant species in the shallowest assemblage instead of Atlantic cod that were dominant in the period before the collapse in the area; redfish is the dominant species in the second shallow and intermediate assemblages. Diversity appears inversely related to biomass in the different assemblages. Despite the collapse in some species and the permanent fishing activity target to the North Shrimp (Pandalus borealis), redfish (Sebastes spp) and Greenland halibut, the overall pattern of demersal fish assemblages remains similar over time. This pattern is similar in other Atlantic areas; it indicates that changes in the fish populations in Northwest Atlantic have been produced on a large scale and are not limited to specific areas

Persistence and Variation on the Groundfish Assemblages on the Southern Grand Banks (NAFO Divisions 3NO): 2002–2011

Data from EU-Spain (Instituto Español de Oceanografía) bottom trawl surveys in the NAFO Regulatory Area (2002–2011) were analyzed to examine patterns on the South of Grand Banks (NAFO Div. 3NO) of groundfish assemblage structure and diversity in relation to depth. The 1160 hauls from the slope surveys spanned between 38 and 1460 m in depth. We focused on the 28 most abundant species, which made up 92.6% of the catch in terms of biomass. Assemblage structure was strongly correlated with depth. For the most part, changes in assemblages seem to be fairly continuous, although there were more abrupt changes at 300 m. Five assemblages were identified. Two shallow assemblages were found in the shelf. Assemblage I (Shallow) comprises the strata with depths lesser than 150 and include yellowtail flounder (Limanda ferruginea), American plaice (Hippoglossoides platessoides), Northern sand lance (Ammodytes dubius), moustache sculpin (Triglops murrayi), capelin (Mallotus villosus) and web sculpin (Hemitripterus americanus). Assemblage II (Shallow) includes the strata with depths between 151 and 300 m and comprises Atlantic cod (Gadus morhua), American angler (Lophius americanus), wolfish (Anarichas lupus) and thorny skate (Amblyraja radiata). Assemblage III (Intermediate) contains the depth strata between 301 and 600 m. Redfish (Sebastes spp.), spotted wolfish (Anarhichas minor), Arctic eelpout (Lycodes reticulatus), Northern wolfish (Anarhichas denticulatus), white hake (Urophycis tenuis), witch flounder (Glyptocephalus cynoglossus) and longfin hake (Phycis chesteri) were included in the intermediate assemblage. Finally, we found two deep clusters: Assemblage IV (Deep) contains the depths between 601 and 1000 m, and Assemblage V (Deep) the depth strata greater than 1001 m. Greenland halibut (Reinhardtius hippoglossoides), marlin-spike (Nezumia bairdii), roughhead grenadier (Macrourus berglax) and spinytail skate (Bathyraja spinicauda) formed Assemblage IV. Snubnosed spiny eel (Notacanthus chemnitzii), blue antimora (Antimora rostrata), Northern cutthroat eel (Syphanobranchus kaupii), roundnose grenadier (Coryphaenoides rupestris), black dogfish (Centroscyllium fabricii), Arctic skate (Amblyraja hyperborean) and longnose chimera (Harriotta raleighana) made up the deepest assemblage. Despite dramatic changes in biomass and abundance of the species in the area, the boundaries and composition of the assemblages seem to be similar to the period before the collapse. Although some changes were evident, the main ones were replacements of the dominant species in several assemblages and bathymetric range extension of distribution of some species. Yellowtail flounder appears to be the dominant species in the shallowest assemblage instead of Atlantic cod and American plaice that were dominant in the period before the collapse in the area; redfish is the dominant species in the second shallow and intermediate assemblages. Diversity appears inversely related to biomass in the different assemblages. Despite the fishing effort in the deep waters of the Grand Banks, the overall pattern of demersal fish assemblages remains similar over time. This pattern is similar in other Atlantic areas; it indicates that changes in the fish populations in Northwest Atlantic have been produced on a large scale and are not limited to specific areas

Higher rates of liana regeneration after canopy fall drives species abundance patterns in central Amazonia

In tropical rainforest, most vascular plants have some capacity to resprout, and lianas are often effective resprouters after canopy fall. However, the diversity of resprouting responses of liana species and the consequence for plant persistence are poorly understood. We hypothesized that variation in regeneration among liana species causes differences in liana species abundance in tropical rainforest through differential resprouting capacity, such that liana species with higher densities produce more resprouts after canopy falls.We applied a manipulative field experiment investigating the effect of different levels of disturbance on the production of resprouts and adventitious roots in 10 liana species of the tribe Bignonieae (Bignoniaceae) with contrasting abundances in central Amazonia. We selected 15 individuals of each species and assigned the lianas to three distinct conditions: (a) total canopy fall with lianas severely damaged and detached from trees; (b) partial fall of lianas, without visible damage; and (c) intact lianas (control). We tested whether liana species regeneration patterns were related to species density. Liana species density was calculated using previous research on liana species distribution in 30 1‐ha plots systematically distributed in a 6 × 6 km2 grid at the Ducke Reserve.The number of aerial resprouts produced by lianas under the total canopy fall treatment was twice that of plants under lower levels of disturbance, while the production of adventitious roots did not differ among treatments. Liana species showed different intensities of resprouting, and species with higher average densities on the forest landscape had more resprouts after the total canopy fall treatment.Synthesis. Our results shed new light on the factors that influence liana species abundance, highlighting the role of resprouting after canopy fall and its variation among liana species. Resprouting mitigates the negative effects of canopy damage, suggesting that the impact of increased tree fall disturbances over time, which has been attributed to Amazonian forests in the literature, may increase already abundant liana species with effective resprouting capacity. We identify liana species that are more resilient to disturbance and may alter forest dynamics during climatic change.Our results shed new light on the factors that influence liana species abundance, highlighting the role of resprouting after canopy fall and its variation among liana species. Resprouting mitigates the negative effects of canopy damage, suggesting that the impact of increased tree fall disturbances over time, which has been attributed to Amazonian forests in the literature, may increase already abundant liana species with effective resprouting capacity. We identify liana species that are more resilient to disturbance and may alter forest dynamics during climatic change.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155931/1/jec13345_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155931/2/jec13345.pd

Combining portable X-ray fluorescence and clustering methods for mineral exploration. A case study in Batigelas (Ossa-Morena Zone, Portugal)

Batigelas is a mineral occurrence in the Alter do Chão-Elvas sector of the Ossa-Morena Zone that was investigated by the Serviço de Fomento Mineiro including soil geochemistry and terrestrial geophysics. The results obtained justified the execution of a drill hole. Recent soil geochemistry work using portable X-ray fluorescence has yielded new results for the region. The application of clustering methods (hierarchical and k-means clustering) to the analyses allowed to detail not only the initial anomaly identified, but also to identify the outcropping of geological units in the region. The results obtained highlight the importance of applying this technique in mineral exploration campaigns

Unlocking the in vitroanti- inflammatory and antidiabetic potential of Polygonum maritimum

Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes. Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L. Material and methods: Antioxidant activity was determined (up to 1mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24 h at concentrations up to 100 mu g/mL and antidiabetic potential was assessed by alpha-amylase and alpha-glucosidase inhibition (up to 10 g/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS). Results: The methanol leaf extract had the highest activity against DPPH center dot (IC50 = 26 mu g/mL) and ABTS1(+)center dot (IC50 = 140 mu g FRAP (IC50 = 48 mu g/mL) and CCA (IC50 = 770 mu g/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC50 = 48 mu g/mL). The methanol root (IC50 = 19 mu g/mL) and leaf (IC50 = 29 mu g/mL) extracts strongly inhibited baker's yeast alpha-glucosidase, but LDCM had higher rat's alpha-glucosidase inhibition (IC50 = 2527 mu g/mL) than acarbose (IC50 = 4638 mu g/mL). GC-MS analysis identified beta-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities. Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.XtremeBio project - Foundation for Science and Technology (FCT) [PTDC/MAR-EST/4346/2012]; Portuguese National Budget; FCT [CCMAR/Multi/04326/ 2013, IF/00049/2012, SFRH/BPD/86071/2012, UID/Multi/00612/2013

Biodegradation kinetics of acenphtylene, flourene and phenantrene : a comparative study

Polycyclic Aromatic Hydrocarbons (PAH) are environmental contaminants produced in many human activities and presents toxic and carcinogenic characteristics. Their low solubility in water leads to slow biodegradation rates and consequently environmental persistence. The present work intends to determine the degradation rates of three aqueous phase PAH’s (acenphtylene, flourene and phenantrene) by a mixed culture of microorganisms. The three PAH were dissolved in water at a concentration approximately of 1 mg Lˉ¹. A mixed culture taken from contaminated site was used to inoculate the samples. Batch experiments were performed at room temperature (∼20°C) and PAH consume was measured during the experiment time. PAH samples were extracted and concentrated by solid phase micro extraction (SPME) and measured by GC-FID. Biomass was measured as volatile suspended solids at the beginning and at the end of experiment to ensure that no significant biomass was grown. The culture was able to degrade acenphtylene, flourene and phenantrene. The biokinetics parameters (k and Ks) were determined using a saturation type kinetics biodegradation model and the results were very similar for the three PAH’s. The main microorganisms identified (by API 20NE test) in the culture were Pseudomonas putida, Pseudomonas aeruginosa, Alcagenes faecalis and Xanthomonas maltophilia

Renormalization, duality, and phase transitions in two- and three-dimensional quantum dimer models

We derive an extended lattice gauge theory type action for quantum dimer models and relate it to the height representations of these systems. We examine the system in two and three dimensions and analyze the phase structure in terms of effective theories and duality arguments. For the two-dimensional case we derive the effective potential both at zero and finite temperature. The zero-temperature theory at the Rokhsar-Kivelson (RK) point has a critical point related to the self-dual point of a class of $Z_N$ models in the $N\to\infty$ limit. Two phase transitions featuring a fixed line are shown to appear in the phase diagram, one at zero temperature and at the RK point and another one at finite temperature above the RK point. The latter will be shown to correspond to a Kosterlitz-Thouless (KT) phase transition, while the former will be governed by a KT-like universality class, i.e., sharing many features with a KT transition but actually corresponding to a different universality class. On the other hand, we show that at the RK point no phase transition happens at finite temperature. For the three-dimensional case we derive the corresponding dual gauge theory model at the RK point. We show in this case that at zero temperature a first-order phase transition occurs, while at finite temperatures both first- and second-order phase transitions are possible, depending on the relative values of the couplings involved.Comment: 16 pages, 3 figure

Orange IV stabilizes silk fibroin microemulsions

Silk fibroin (SF) is a natural biopolymer that has been extensively studied in various applications due to its impressive mechanical properties and biocompatibility. Recently, SF-based particles have been proposed as controlled drug delivery systems. A new and efficient method to prepare SF microemulsions (SF-MEs) was developed by oil-in-water emulsions using high-pressure homogenization to promote emulsification. During SF-ME production, the secondary structure of SF changed to a more stable conformation (from random coil to -sheets), thus allowing the formation of small and stable (140.7 ± 1.9 nm; polydispersity index, 0.25) SF microparticles (SF-MPs). The efficiency of SF-MP formation was 60%. Orange IV was used as a model compound for incorporation and release studies, although its incorporation into the SF-MEs significantly improved particle size and size distribution over at least 4 wk compared to traditional stabilizers (e.g., poloxamer 407, transcutol, Tween 80, and SDS). This should be a call of attention when using dyes as model compounds since they can influence particle properties and lead to misinterpretation of the results. Orange IV showed an incorporation efficiency of 91% and a controlled release over time. Stable SF-MP formulations, further enhanced by orange IV incorporation, provide an innovative method with potential application in pharmaceutical development due to its associated high biocompatibility and release profile.The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioHealth - Biotechnology and Bioengineering Approaches to Improve Health Quality," Ref. NORTE-07-0124-FEDER-000027, cofunded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. We would also like to acknowledge CRA - Unita di Ricerca di Apicoltura and Bachicoltura Padova (Italy) for the supply of B. mori silkworm cocoons, and Andreia Vasconcelos for technical support