Do Mentoring Programs Make a Difference? A Qualitative Case Study on the Journey of Latino Students in a STEM Track

A number of studies have sought to identify factors influencing STEM students’ success in colleges and universities (Crisp et al., 2009; Excelencia, 2011; Hagedorn & Purnamasari, 2012). However, there are few qualitative studies focusing on students’ perspectives and how they make meaning of their experiences as participants in a mentoring program. The main purpose of this research was to explain the perceptions of Latino students in a STEM Mentoring Program at Miami Dade College. Because this study sought to gain an in-depth understanding of how students involved in a mentoring program make meaning of their experiences, the type of qualitative research that fits this inquiry was a single case study. This study was undertaken to address these questions: (a) How do STEM students make meaning of mentorship? (b) How do STEM students construct their experiences in the Program? (c) To what extent do gender and ethnicity play a role in how students make meaning of their mentoring experiences? (d) What do students identify as important for succeeding in a mentorship program? The major findings of this study were: (1) For the participants, a formal mentoring programs offers various forms of academic support, but they found interpersonal support with informal mentors; (2) For the participants, in a formal mentoring program a career match between mentor and mentee is essential; (3) For the participants, the required number of meetings in a formal mentoring program was burdensome, but other required activities were important; (4) For the participants, the peer mentoring experience was important and self-fulfilling; (5) For the participants, the gender or race of the mentor was insignificant, but some believed that sharing the same cultural background made them feel more connected with their majors; and (6) For the participants, encouragement and emotional support from their families was important, but only those with college-educated parents received the academic and financial support necessary important to succeed in college; (7) For the participants, a mentoring program will be successful if there are opportunities for building community among students and faculty, but ultimately, what matters for success are the personal characteristics of students. This study was significant because it provided insight into what students understand are key experiences of being in a mentoring program, and it also identified the kinds of institutional support students themselves thought would help in STEM careers. This information can help institutions of higher education plan and administer effective mentoring programs in STEM or even other fields

Multitransitional observations of the CS core of L673

A multitransitional study with the BIMA interferometric array was carried out toward the starless core found in the L673 region, in order to study the small-size structure of the cores detected with previous single--dish observations, which provides us with a test of the predictions of the chemical model of Taylor et al. (1996; 1998). We detected emission in the CS (2-1), N2H+ (1-0), and HCO+ (1-0) lines. Several clumps of size ~0.08 pc were found for each line distributed all over the region where previous single-dish emission was found (Morata et al. 1997). Each molecular transition traces differently the clump distribution, although in some cases the detected clumps are coincident. The distribution of the N2H+ emission and the single-dish NH3 emission are coincident and compatible with an origin in the same gas. The large fraction of missing flux measured for the CS (2-1) transition can be explained if the cloud is formed by a clumpy and heterogeneous medium. Four positions were selected to derive the abundance ratios [N2H+/CS] and [HCO+/CS] from the molecular column density determinations, and to compare them with the values predicted by the chemical model. The model was able to explain the interferometric observations, and, in particular, the chemical differentiation of the detected clumps and the coincidence of the NH3 and N2H+ emissions. The lack of HCO+ towards the two selected positions that trace the more evolved clumps cannot be accounted for by the model, but it is possibly due to strong self-absorption. We propose a classification of the studied clumps according to the stage of chemical evolution indicated by the molecular abundances.Comment: 10 pages, 9 figures, accepted for publication in A&

Evidence for transient clumps and gas chemical evolution in the CS core of L673

We present FCRAO maps as well as combined BIMA and FCRAO maps of the high density molecular emission towards the CS core in the L673 region. With the FCRAO telescope, we mapped the emission in the CS(2-1), C34S(2-1), HCO+(1-0), and H13CO+(1-0) lines. The high density molecular emission, which arises from a filamentary structure oriented in the NW-SE direction, shows clear morphological differences for each molecule. We find that HCO+ has an extremely high optical depth, and that the H13CO+ emission is well correlated with submm sources. The BIMA and FCRAO combined maps recover emission from a lot of other structure which was previously undetected or only marginally detected, and show an overall aspect of a filamentary structure connecting several intense clumps. We found a total 15 clumps in our combined data cube, all of them resolved by our angular resolution, with diameters in the 0.03-0.09 pc range. We find a clear segregation between the northern and southern region of the map: the northern section shows the less chemically evolved gas and less massive but more numerous clumps, while the southern region is dominated by the largest and most massive clump, and contains the more evolved gas, as traced by emission of late-time molecules. We find that the derived clump masses are below the virial mass, and that the clumps masses become closer to the virial mass when they get bigger and more massive. This supports the idea that these clumps must be transient, and only the more massive ones have a chance to last long enough to form stars. The clumps we detect are probably in an earlier evolutionary stage than the ``starless cores'' reported recently in the literature. Only the most massive one has properties similar to a ``starless core''.Comment: 12 pages, 8 figures, accepted for publication in Astronomy & Astrophysics; minor revisions after language editin

Improved thermal isolation of silicon suspended platforms for an all-silicon thermoelectric microgenerator based on large scale integration of Si nanowires as thermoelectric material

Special suspended micro-platforms have been designed as a part of silicon compatible planar thermoelectric microgenerators. Bottom-up grown silicon nanowires are going to bridge in the future such platforms to the surrounding silicon bulk rim. They will act as thermoelectric material thus configuring an all-silicon thermoelectric device. In the new platform design other additional bridging elements (usually auxiliary support silicon beams) are substituted by low conductance thin film dielectric membranes in order to maximize the temperature difference developed between both areas. These membranes follow a sieve-like design that allows fabricating them with a short additional wet anisotropic etch step. © Published under licence by IOP Publishing Ltd.Peer ReviewedPostprint (published version

Monte Carlo simulations of H2 formation on stochastically heated grains

Continuous-time, random-walk Monte Carlo simulations of H2 formation on grains have been performed for surfaces that are stochastically heated by photons. We have assumed diffuse cloud conditions and used a variety of grains of varying roughness and size based on olivine. The simulations were performed at different optical depths. We confirmed that small grains (r <= 0.02 micron) have low modal temperatures with strong fluctuations, which have a large effect on the efficiency of the formation of molecular hydrogen. The grain size distribution highly favours small grains and therefore H2 formation on these particles makes a large contribution to the overall formation rate for all but the roughest surfaces. We find that at A_V=0 only the roughest surfaces can produce the required amount of molecular hydrogen, but by A_V=1, smoother surfaces are possible alternatives. Use of a larger value for the evaporation energy of atomic hydrogen, but one still consistent with experiment, allows smoother surfaces to produce more H2.Comment: MNRAS LaTeX, 10 pages, 11 eps-figures to be published in MNRA

Influence of Organic Enrichment and Spisula subtruncata (da Costa, 1778) on Oxygen and Nutrient Fluxes in Fine Sand Sediments

[EN] The role of labile organic material and macrofaunal activity in benthic respiration and nutrient regeneration have been tested in sublittoral fine sand sediments from the Gulf of Valencia (northwestern Mediterranean Sea). Three experimental setups were made using benthic chambers. One experiment was performed in-situ through the annual cycle in a well-sorted fine sand community. The remaining experiments were carried out with mesocosms under laboratory conditions: one with different concentrations of organic enrichment (mussel meat and concentrated diatoms culture), and the other adding two different densities of the endofaunal bivalve Spisula subtruncata. Biochemical variables in surface sediment and changes in oxygen consumption and nutrient fluxes throughout incubation period were studied in each experiment. In the in situ incubations, dissolved oxygen (DO) fluxes showed a strong correlation with sedimentary biopolymeric fraction of organic carbon. Organic enrichment in the laboratory experiments was responsible for increased benthic respiration. However, sediment response (expressed as DO uptake and dissolved inorganic nitrogen—DIN—release) between oligotrophic and eutrophic conditions was more intense than between eutrophic and hypertrophic conditions. S. subtruncata abundances close to 400 and 850 ind m−2 also intensified benthic metabolism. DO uptake and DIN production in mesocosms with added fauna were between 60 and 75 % and 65–100 % higher than in the control treatment respectively. The results of these three experiments suggest that the macrobenthic community may increase the benthic respiration by roughly a factor of two in these bottoms, where S. subtruncata is one of the dominant species. Both organic enrichment and macrobenthic community in general, and S. subtruncata in particular, did not seem to have a relevant role in P and Si cycles in these sediments.This research was supported by the Conselleria d'Educacio (Generalitat Valenciana). We are very grateful for the valuable comments of anonymous reviewers on previous version of the manuscript.Sospedra, J.; Falco, S.; Morata, T.; Rodilla, M. (2016). Influence of Organic Enrichment and Spisula subtruncata (da Costa, 1778) on Oxygen and Nutrient Fluxes in Fine Sand Sediments. Estuaries and Coasts. doi:10.1007/s12237-016-0174-1SAller, R.C., and J.Y. Aller. 1998. The effect of biogenic irrigation intensity and solute exchange on diagenetic reaction rates in marine sediments. Journal of Marine Research 56: 905–936.Aminot, A., and M. Chaussepied. 1983. Manuel des analyses chimiques en milieu marin. Brest: Centre National pour l’Exploitation des Oceans.Arnosti, C., and M. Holmer. 2003. Carbon cycling in a continental margin sediment: contrasts between organic matter characteristics and remineralization rates and pathways. Estuarine, Coastal and Shelf Science 58: 197–208.Baptist, M.J., and M.F. Leopold. 2009. The effects of shoreface nourishments on Spisula and scoters in The Netherlands. Marine Environmental Research 68: 1–11.Bartoli, M., D. Nizzoli, P. Viaroli, and E. Turolla. 2001. Impact of Tapes philippinarum farming on nutrient dynamics and benthic in the Sacca di Goro. Hydrobiologia 455: 203–212.Bellan-Santini, D., J.C. Lacaze, and C. Poizat. 1994. Les biocénoses marines et littorals de Méditerranées, synthèse, menaces et perspectives, Patrimoines naturels, 19. Paris: Secrétariat de la fauna et de la flore, MNHN.Beninger, P.G., and S.D. St-Jean. 1997. The role of mucus in particle processing by suspension-feeding marine bivalves: unifying principles. Marine Biology 129: 389–397.Biles, C.L., M. Solan, I. Isaksson, D.M. Paterson, C. Emes, and D.G. Raffaelli. 2003. Flow modifies the effect of biodiversity on ecosystem functioning: an in situ study of estuarine sediments. Journal of Experimental Marine Biology and Ecology 285-286: 165–177.Borja, A., J. Franco, and V. Pérez. 2000. A marine biotic index to establish the ecological quality of soft-bottom benthos within European estuarine and coastal environments. Marine Pollution Bulletin 40: 1100–1114.Boudreau, B.P., M. Huettel, S. Forster, R.A. Jahnke, A. McLachlan, J.J. Middelburg, P. Nielsen, F. Sansone, G. Taghon, W. Van Raaphorst, I. Webster, J.M. Weslawski, P. Wiberg, and B. Sundby. 2001. Permeable marine sediments: overturning an old paradigm. EOS. Transactions American Geophysical Union 82: 133–136.Braber, L., and S.J. De Groot. 1973. The food of five flatfish species (Pleuronectiformes) in the southern North Sea. Journal of Sea Research 6: 163–172.Canal-Verges, P., M. Vedel, T. Valdemarsen, E. Kristensen, and M.R. Flindt. 2010. Resuspension created by bedload transport of macroalgae: implications for ecosystem functioning. Hydrobiologia 649: 69–76.Canfield, D.E., B.B. Jorgensen, H. Fossing, R. Glud, J. Gundersen, N.B. Ramsing, B. Thamdrup, J.W. Hansen, L.P. Nielsen, and P.O.J. Hall. 1993. Pathways of organic carbon oxidation in three continental margin sediments. Marine Geology 113: 27–40.Carlsson, M.S., R.N. Glud, and J.K. Petersen. 2010. Degradation of mussel (Mytilus edulis) fecal pellets released from hanging long-lines upon sinking and after settling at the sediment. Canadian Journal of Fisheries and Aquatic Sciences 67(9): 1376–1387.Castelli, A., C. Lardicci, and D. Tagliapietra. 2004. Soft-bottom macrobenthos. In Mediterranean Marine Benthos: A Manual of methods for its sampling and study Vol. 11 (Suppl. 1), ed. Maria Cristina Gambi, and Marco Dappiano, 99–131. Genova: Biologia Marina Mediterranea.Clark, R.B. 2002. Marine pollution, 5th edn. Oxford: Oxford University Press.Cloern, J.E. 2001. Our evolving conceptual model of the coastal eutrophication problem. Marine Ecology Progress Series 210: 223–253.Colijn, F., and V.N. de Jonge. 1984. Primary production of microphytobenthos in the Ems-Dollar Estuary. Marine Ecology Progress Series 14: 185–196.Cotano, U., and F. Villate. 2006. Anthropogenic influence on the organic fraction of sediments in two contrasting estuaries: a biochemical approach. Marine Pollution Bulletin 52: 404–414.Danovaro, R., and M. Fabiano. 1997. Seasonal changes in quality and quantity of food available for benthic suspension-feeders in the Golfo Marconi (North-western Mediterranean. Estuarine, Coastal and Shelf Science 44: 723–736.Danovaro, R., D. Marrale, N. Della Croce, P. Parodi, and M. Fabiano. 1999. Biochemical composition of sedimentary organic matter and bacterial distribution in the Aegean Sea: trophic state and pelagic-benthic coupling. Journal of Sea Research 42: 117–129.Dauer, D.M. 1993. Biological criteria, environmental health and estuarine macrobenthic community structure. Marine Pollution Bulletin 26(5): 249–257.Dauwe, B., P.M.J. Herman, and C.H.R. Heip. 1998. Community structure and bioturbation potential of macrofauna at four North Sea stations with contrasting food supply. Marine Ecology Progress Series 173: 67–83.De Vittor, C., F. Relitti, M. Kralj, S. Covelli, and A. Emili. 2015. Oxygen, carbon, and nutrient exchanges at the sediment-water interface in the Mar Piccolo of Taranto (Ionian Sea, southern Italy). Environmental Science and Pollution Research. doi: 10.1007/s11356-015-4999-0 .Degraer, S., P. Meire, and M. Vincx. 2007. Spatial distribution, population dynamics and productivity of Spisula subtruncata: implications for Spisula fisheries in seaduck wintering areas. Marine Biology 152(4): 863–875.Dell’Anno, A., M.L. Mei, A. Pusceddu, and R. Danovaro. 2002. Assessing the trophic state and eutrophication of coastal marine systems: a new approach base on the biochemical composition of sediment organic matter. Marine Pollution Bulletin 44: 611–622.Demestre, M., Guillén, J., Soriano, S., Palanques, A., Sánchez, P., Puig, P. and L. Recasens. 2007. Vertical distribution of benthic communities and bioturbation rates in the sediment of the inner shelf. Rapport Commission International pour l’exploration scientifique de la Mer Mediterraneé 38.Deval, C.M., and D. Göktürk. 2008. Population structure and dynamics of the cut through Shell Spisula subtruncata (da Costa) in the Sea of Marmara, Turkey. Fisheries Research 89: 241–247.Ehrenhauss, S., and M. Huettel. 2004. Advective transport and decomposition of chain-forming planktonic diatoms in permeable sediments. Journal of Sea Research 52: 179–197.Emmerson, M.C., M. Solan, C. Emes, D.M. Paterson, and D. Raffaelli. 2001. Consistent patterns and the idiosyncratic effects of biodiversity in marine ecosystems. Nature 411: 73–77.Fabiano, M., D. Marrale, and C. Misic. 2003. Bacteria and organic dynamics during a bioremediation treatment of organic-rich harbour sediments. Marine Pollution Bulletin 46: 1164–1173.Fichez, R. 1991. Composition and fate of organic matter in submarine cave sediments; implications for the biogeochemical cycle of organic carbon. Oceanologica Acta 14: 369–377.Fogarty, M.J., M.P. Sissenwine, and E.B. Cohen. 1991. Recruitment variability and the dynamics of exploited populations. Trends in Ecology & Evolution 6: 241–246.Fraschetti, S., A. Covazzi, M. Chiantore, and G. Albertelli. 1997. Life-history traits of the bivalve Spisula subtruncata (da Costa) in the Ligurian Sea (North-Western Mediterranean): the contribution of newly settled juveniles. Scientia Marina 61(2): 25–32.Fuentes, A., I. Fernández-Segovia, I. Escriche, and J.A. Serra. 2009. Comparison of physico-chemical parameters and composition of mussels (Mytilus galloprovincialis Lmk.) from different Spanish origins. Food Chemistry 112: 295–302.Gadea, I., M. Rodilla, J. Sospedra, S. Falco, and T. Morata. 2013. Seasonal dynamics of the phytoplankton community in the Gandia coastal area, Southern Gulf of Valencia. Thalassas 29(1): 37–60.Gerino, M. 1990. The effects of bioturbation on particle distribution in Mediterranean coastal sediment. Preliminary result. Hydrobiologia 207: 251–258.GIG. 2008. WFD Intercalibration technical report for coastal and transitional waters in the Mediterranean ecoregion. In: WFD Intercalibration Technical Report–Part 3: Coastal and Transitional Waters. Available from: http://publications.jrc.ec.europa.eu/repository/bitstream/111111111/10473/1/3010_08-volumecoast.pdf . Accessed 11 Nov 2015.Gilbert, F., P. Bonin, and G. Stora. 1995. Effect of bioturbation on denitrification in a marine sediment from the Western Mediterranean littoral. Hydrobiolgia 304: 49–58.Glud, R. 2005. Marine eutrophication and benthic metabolism. In Drainage basin nutrient inputs and eutrophication: an integrated approach, eds. Paul Wassmann and Kalle Olli, 147–154. Norway: University of Tromsø.Hargrave, B.T., M. Holmer, and C.P. Newcombe. 2008. Towards a classification of organic enrichment in marine sediments based on biogeochemical indicators. Marine Pollution Bulletin 56(5): 810–824.Heilskov, A.C., and M. Holmer. 2001. Effects of benthic fauna on organic matter mineralization in fish-farm sediments: importance of size and abundance. Journal of Marine Science 58: 427–434.Heilskov, A.C., M. Alperin, and M. Holmer. 2006. Benthic fauna bio-irrigation effects on nutrient regeneration in fish farm sediments. Journal of Experimental Marine Biology and Ecology 339: 204–225.Holmer, M., and E. Kristensen. 1994. Anaerobic mineralization of fish farmwaste products in organic-rich sediments. In Changes in Fluxes in Estuaries, ed. Keith R. Dyer, and Robert Joseph Orth, 283–289. Denmark: Olsen and Olsen.Holmer, M., C.M. Duarte, and N. Marbá. 2003. Sulfur cycling and seagrass (Posidonia oceanica) status in carbonate sediments. Biogeochemistry 66: 223–239.Hooper, D.U., F.S. Chapin III, J.J. Ewel, A. Hector, P. Inchausti, S. Lavorel, J.H. Lawton, D.M. Lodge, M. Loreau, S. Naeem, B. Schmid, H. Setälä, A.J. Symstad, J. Vandermeer, and D.A. Wardle. 2005. Effects of biodiversity on ecosystem functioning: a consensus of current knowledge. Ecological Monographs 75(1): 3–35.Huettel, M., P. Berg, and J.E. Kostka. 2014. Benthic exchange and biogeochemical cycling in permeable sediments. Annual Review of Marine Science 6: 23–51.Jørgensen, B.B., and M.P. Revsbech. 1985. Diffusive boundary layers and the oxygen uptake of sediments and detritus. Limnology and Oceanography 30(1): 111–122.Karlson, K., S. Hulth, K. Ringdahl, and R. Rosenberg. 2005. Experimental recolonization of Baltic Sea reduced sediments: survival of benthic macrofauna and effects on nutrient cycling. Marine Ecology Progress Series 294: 35–49.Kristensen, E., G. Penha-Lopes, M. Delefosse, T. Valdemarsen, C.O. Quintana, and G.T. Banta. 2012. What is bioturbation? The need for a precise definition for fauna in aquatic sciences. Marine Ecology Progress Series 446: 285–302.Laverock, B., J.A. Gilbert, K. Tait, A.M. Osborn, and S. Widdicombe. 2011. Bioturbation: impact on the marine nitrogen cycle. Biochemical Society Transactions 39(1): 315–320.Lewis, C.V.W., J.R. Weinberg, and C.S. Davis. 2001. Population structure and recruitment of the bivalve Arctica islandica (Linnaeus, 1767) on Georges Bank from 1980-1999. Journal of Shellfish Research 20: 1135–1144.Lohrer, A.M., S.F. Thrush, and M.M. Gibbs. 2004. Bioturbators enhance ecosystem function through complex biogeochemical interactions. Nature 431: 1092–1095.López, N.I., C.M. Duarte, F. Vallespinós, J. Romero, and T. Alcoverro. 1998. The effect of nutrient additions on bacterial activity in seagrass (Posidonia oceanica) sediments. Journal of Experimental Marine Biology and Ecology 224: 155–165.Lundkvist, M., M. Grue, P.L. Friend, and M.R. Flindt. 2007. The relative contributions of physical and microbiological factors to cohesive sediment stability. Continental Shelf Research 27(8): 1143–1152.Mantoura, R.F.C., J.-M. Martin, and R. Wollast. 1991. Ocean margin process in global change. Chichester: Wiley & Sons.Martinez-Garcia, E., M.S. Carlsson, P. Sanchez-Jerez, J.L. Sánchez-Lizaso, C. Sanz-Lazaro, and M. Holmer. 2015. Effect of sediment grain size and bioturbation on decomposition of organic matter from aquaculture. Biogeochemistry 125: 133–148.Mayer, P., V.D. Estruch, and M. Jover. 2012. A two-stage growth model for gilthead sea bream (Sparus aurata) based on the thermal growth coefficient. Aquaculture 358-359: 6–13.McKindsey, C.W., P. Archambault, M.D. Callier, and F. Olivier. 2011. Influence of suspended and off-bottom mussel culture on the sea bottom and benthic habitats: a review. Canadian Journal of Zoology 89(7): 622–646.Mermillod-Blondin, F., and R. Rosenberg. 2006. Ecosystem engineering: the impact of bioturbation on biogeochemical processes in marine and freshwater benthic habitats. Aquatic Sciences 68: 434–442.Mermillod-Blondin, F., F. François-Carcaillet, and R. Rosenberg. 2005. Biodiversity of benthic invertebrates and organic matter processing in shallow marine sediments: an experimental study. Journal of Experimental Marine Biology and Ecology 315: 187–209.Michaud, E., G. Desrosiers, F. Mermillod-Blondin, B. Sundby, and G. Stora. 2005. The functional group approach to bioturbation: the effects of biodiffusers and gallery-diffusers of the Macoma balthica community on sediment oxygen uptake. Journal of Experimental Marine Biology and Ecology 326: 77–88.Moodley, L., M. Steyaert, E. Epping, J.J. Middelburg, M. Vincx, P. van Avesaath, T. Moens, and K. Soetaert. 2008. Biomass-specific respiration rates of benthic meiofauna: demonstrating a novel oxygen micro-respiration system. Journal of Experimental Marine Biology and Ecology 357: 41–47.Morata, T., J. Sospedra, S. Falco, and M. Rodilla. 2012. Exchange of nutrients and oxygen across the sediment-water interface below a Sparus aurata marine fish farm in the north-western Mediterranean Sea. Journal of Soils and Sediments 12(10): 1623–1632.Morata, T., S. Falco, J. Sospedra, I. Gadea, and M. Rodilla. 2014. Benthic recovery after the cessation of a gilt-head seabream, Sparus aurata, farm in the Mediterranean Sea. Journal of the World Aquaculture Society. 45(4): 380–391.Mortimer, R.J.G., J.T. Davey, M.D. Krom, P.G. Watson, P.E. Frickers, and R.J. Clifton. 1999. The effect of macrofauna on porewater profiles and nutrient fluxes in the intertidal zone of the Humber Estuary. Estuarine, Coastal and Shelf Science 48: 683–699.Newell, R. 1979. Biology of intertidal animals, 3ª edn. Faversham: Marine Ecological Surveys.Pastor, L., B. Deflandre, E. Viollier, C. Cathalot, E. Metzger, C. Rabouille, K. Escoubeyrou, E. Lloret, A.M. Pruski, G. Vétion, M. Desmalades, R. Buscail, and A. Grémare. 2011. Influence of the organic matter composition on benthic oxygen demand in the Rhône River prodelta (NW Mediterranean Sea. Continental Shelf Research 31: 1008–1019.Pearson, T., and R. Rosenberg. 1978. Macrobenthic succession in relation to organic enrichment and pollution of the marine environment. Oceanography and Marine Biology 16: 229–311.Pernetta, J.C., and J.D. Milliman. 1995. Land-ocean interactions in the coastal zone. Implementation plan. Stockholm: IGBP.Piedecausa, M.A., F. Aguado-Giménez, J. Cerezo, M.D. Hernández, and B. García-García. 2012. Influence of fish food and faecal pellets on short-term oxygen uptake, ammonium flux and acid volatile sulphide accumulation in sediments impacted by fish farming and non-impacted sediments. Aquaculture Research 43: 66–74.Pihl, L., and R. Rosenberg. 1984. Food selection and consumption of the shrimp Crangon crangon in some shallow marine areas in western Sweden. Marine Ecology Progress Series 15: 159–168.Pratihary, A.K., S.W.A. Naqvi, H. Naik, B.R. Thorat, G. Narvenkar, B.R. Manjunatha, and V.P. Rao. 2009. Benthic fluxes in a tropical Estuary and their role in the ecosystem. Estuarine, Coastal and Shelf Science 85: 387–398.Pusceddu, A., A. Dell’Anno, M. Fabiano, and R. Danovaro. 2004. Quantity and biochemical composition of organic matter in marine sediments. In Mediterranean Marine Benthos: A Manual of methods for its sampling and study Vol. 11 (Suppl. 1), ed. Maria Cristina Gambi, and Marco Dappiano, 39–53. Genova: Biologia Marina Mediterranea.Pusceddu, A., A. Dell’Anno, M. Fabiano, and R. Danovaro. 2009. Quantity and bioavailability of sediment organic matter as signature of benthic trophic status. Marine Ecology Progress Series 375: 41–52.Pusceddu, A., S. Bianchelli, C. Gambi, and R. Danovaro. 2011. Assessment of benthic trophic status of marine coastal ecosystems: significance of meiofaunal rare taxa. Estuarine, Coastal and Shelf Science 93: 420–430.Queirós, A.M., S.N.R. Birchenough, J. Bremner, J.A. Godbold, R.E. Parker, A. Romero-Ramirez, H. Reiss, M. Solan, P.J. Somerfield, C. Van Colen, G. Van Hoey, and S. Widdicombe. 2013. A bioturbation classification of European marine infaunal invertebrates. Ecology and Evolution 3(11): 3958–3985.Raffaelli, D.G., J.A. Raven, and L.J. Poole. 1998. Ecological impact of green macroalgal blooms. Oceanography and Marine Biology, An Annual Review 36: 97–126.Røy, H., M. Hüttel, and B.B. Jørgensen. 2002. The role of small-scale sediment topography for oxygen flux across the diffusive boundary layer. Limnology and Oceanography 47(3): 837–847.Rueda, J.L., and A.C. Smaal. 2004. Variation of the physiological energetics of the bivalve Spisula subtruncata (da Costa, 1778) within an annual cycle. Journal of Experimental Marine Biology and Ecology 301: 141–157.Rullkötter, J. 2006. Organic matter: the driving force for early diagenesis. In Marine geochemistry, eds. Horst D. Schulz and Matthias Zabel, 125–168. Berlin: Springer-Verlag.Sardá, R., S. Pinedo, A. Gremare, and S. Taboada. 2000. Changes in the dynamics of shallow-bottom assemblages due to sand extraction in the Catalan Western Mediterranean Sea. ICES Journal of Marine Science 57: 1446–1453.Sebastiá, M.-T., and M. Rodilla. 2013. Nutrient and phytoplankton analysis of a Mediterranean coastal area. Environmental Management 51: 225–240.Sebastiá, M.-T., M. Rodilla, S. Falco, and J.-A. Sanchis. 2013. Analysis of the effects of wet and dry seasons on a Mediterranean river basin: consequences for coastal waters and its quality management. Ocean & Coastal Management 78: 45–55.Smith, V.H. 2002. Eutrophication of freshwater and coastal marine ecosystems. A global problem. Environmental Science and Pollution Research 10(2): 126–139.Solan, M., P. Batty, M.T. Bulling, and J.A. Godbold. 2008. How biodiversity affects ecosystem processes: implications for ecological revolutions and benthic ecosystem function. Aquatic Biology 2: 289–301.Sospedra, J., S. Falco, T. Morata, I. Gadea, and M. Rodilla. 2015. Benthic fluxes of oxygen and nutrients in sublittoral fine sands in a north-western Mediterranean coastal area. Continental Shelf Research 97: 32–42.Thamdrup, B., J.W. Hansen, and B.B. Jørgensen. 1998. Temperature dependence of aerobic respiration in a coastal sediment. FEMS Microbiology Ecology 25: 189–200.Venturini, N., A.L. Pita, E. Brugnoli, F. García-Rodríguez, L. Burone, N. Kandratavicius, M. Hutton, and P. Muniz. 2012. Benthic trophic status of sediments in a metropolitan area (Rio de la Plata estuary): Linkages with natural and human pressures. Estuarine, Coastal and Shelf Science 112: 139–152.Viaroli, P., M. Bartoli, C. Bondavalli, R.R. Christian, G. Giordani, and M. Naldi. 1996. Macrophyte communities and their impact on benthic fluxes of oxygen, sulphide and nutrients in shallow eutrophic environments. Hydrobiologia 329: 105–119

Impact of the application of monosilicic acid to grapevine (Vitis vinifera L.) on the chemical composition of young red Mencia wines

Impact of applying monosilicic acid to grapevines during ripening on chemical composition of Mencía red wines in an area where fungal diseases during summer are common was examined. The foliar application of monosilicic acid to grapevines led to a less oxidized wine, with lower levels of acetic acid, acetaldehyde, ethyl acetate and diacethyl; this should be considered as positive from a sensory point of view. Wines made with silicon-treated grapes also contained lower levels of gluconic acid and glycerol, which are chemical markers of wines made with botrytized grapes, as well as higher contents of total phenols, anthocyanins and tannins. Furthermore, the contents of several mid-chain alcohols were higher (p < 0.05) in wines made with grapes from silicon-treated plantsThe authors gratefully acknowledge the financial support by the FEDER/Spanish Ministry of Science, Innovation, and Universities Project: RTI2018-096268-B-I00. This work was partially supported by Comunidad de Madrid (Spain) and Structural Funds 2014–2020 (ERDF and ESF) (Project AGRISOST-CM S2018/BAA-4330

Diagnosis and numerical simulations of a heavy rain event in the Western Mediterranean Basin

International audienceThe heavy rain event of November 2001 in the western Mediterranean area was synoptically characterized by the presence of a long-lived Omega blocking geopotential pattern. A set of mesoscale numerical simulations using MM5 is performed to investigate the mechanisms responsible for the convection development through several output diagnosis. A potential vorticity evolution showed how dry air masses were extruded from the stratospheric levels promoting strong cyclonic circulation at all levels. Moreover, a deep vertical column of high relative humidity over the Algerian coastline maintained the few and geographically confined convective cells responsible for the heavy precipitation. Mesoscale environment parameters indicated enhanced conditional instability through a deep troposphere layer. Also, strong vertical wind shear values, higher than 50 ms?1 over the troposphere, were derived, indicating enough strength to promote necessary conditions to organize and keep mesoscale convective structures

Molecular Line Observations of the Small Protostellar Group L1251B

We present molecular line observations of L1251B, a small group of pre- and protostellar objects, and its immediate environment in the dense C18O core L1251E. These data are complementary to near-infrared, submillimeter and millimeter continuum observations reported by Lee et al. (2006, ApJ, 648, 491; Paper I). The single-dish data of L1251B described here show very complex kinematics including infall, rotation and outflow motions, and the interferometer data reveal these in greater detail. Interferometer data of N2H+ 1-0 suggest a very rapidly rotating flattened envelope between two young stellar objects, IRS1 and IRS2. Also, interferometer data of CO 2-1 resolve the outflow associated with L1251B seen in single-dish maps into a few narrow and compact components. Furthermore, the high resolution data support recent theoretical studies of molecular depletions and enhancements that accompany the formation of protostars within dense cores. Beyond L1251B, single-dish data are also presented of a dense core located ~150" to the east that, in Paper I, was detected at 850 micron but has no associated point sources at near- and mid-infrared wavelengths. The relative brightness between molecules, which have different chemical timescales, suggests it is less chemically evolved than L1251B. This core may be a site for future star formation, however, since line profiles of HCO+, CS, and HCN show asymmetry with a stronger blue peak, which is interpreted as an infall signature.Comment: 46 pages, 18 figures. Accepted for publication in Ap