Dominance of unicellular cyanobacteria in the diazotrophic community in the Atlantic Ocean

ABSTRACT: The horizontal and vertical distribution of representatives of diazotrophic unicellular cyanobacteria was investigated in the subtropical northeast Atlantic Ocean (28.87 to 42.00°N; 9.01 to 20.02°W). Samples from stations encompassing different water conditions (from oceanic oligotrophic waters to upwelling areas and a temperature range of 13.1°C to 24.2°C) were size fractionated and analyzed for nifH by a nested polymerase chain reaction (PCR) and by tyramide signal amplification–fluorescence in situ hybridization (TSA-FISH) using probe Nitro821. In samples from the surface, mixed-layer depth, and deep chlorophyll maximum waters, most (> 50%) of the nifH recovered was from the 0.2–3 µm fraction and was consistent with TSA-FISH counts. The < 3 µm Nitro821-positive cells were more abundant than the larger cells, and the proportion of single cells was larger than that associated with particulate matter or with larger cells. Phylogenetic analysis of representative samples revealed that most of the sequences belong to diazotrophic unicellular cyanobacteria Group A (UCYN-A or Candidatus Atelocyanobacterium thalassa). N2 fixation in the 0.2–3 µm fraction, putatively representing the activity of UCYN-A, contributed more than 50% of the total N2 fixation. There was a positive relationship of this putative UCYN-A abundance and activity with temperature, and a negative relationship with dissolved O2. The dominance of these putative UCYN-A organisms in nitrate-rich upwelling filament regions suggests that the activity of this group of organisms may not be strongly controlled by the availability of fixed N

Relación entre el índice de esclerofilia y el contenido de clorofila total por unidad de peso seco en algunas especies arbustivas de encinar en Mallorca

Abstract not availabl

Autocorrelation analysis for the unbiased determination of power-law exponents in single-quantum-dot blinking

We present an unbiased and robust analysis method for power-law blinking statistics in the photoluminescence of single nano-emitters, allowing us to extract both the bright- and dark-state power-law exponents from the emitters' intensity autocorrelation functions. As opposed to the widely-used threshold method, our technique therefore does not require discriminating the emission levels of bright and dark states in the experimental intensity timetraces. We rely on the simultaneous recording of 450 emission timetraces of single CdSe/CdS core/shell quantum dots at a frame rate of 250 Hz with single photon sensitivity. Under these conditions, our approach can determine ON and OFF power-law exponents with a precision of 3% from a comparison to numerical simulations, even for shot-noise-dominated emission signals with an average intensity below 1 photon per frame and per quantum dot. These capabilities pave the way for the unbiased, threshold-free determination of blinking power-law exponents at the micro-second timescale

Sequential drain amylase to guide drain removal following pancreatectomy

BACKGROUND: Although used as criterion for early drain removal, postoperative day (POD) 1 drain fluid amylase (DFA) ≤ 5000 U/L has low negative predictive value for clinically relevant postoperative pancreatic fistula (CR-POPF). It was hypothesized that POD3 DFA ≤ 350 could provide further information to guide early drain removal. METHODS: Data from a pancreas surgery consortium database for pancreatoduodenectomy and distal pancreatectomy patients were analyzed retrospectively. Those patients without drains or POD 1 and 3 DFA data were excluded. Patients with POD1 DFA ≤ 5000 were divided into groups based on POD3 DFA: Group A (≤350) and Group B (>350). Operative characteristics and 60-day outcomes were compared using chi-square test. RESULTS: Among 687 patients in the database, all data were available for 380. Fifty-five (14.5%) had a POD1 DFA > 5000. Among 325 with POD1 DFA ≤ 5000, 254 (78.2%) were in Group A and 71 (21.8%) in Group B. Complications (35 (49.3%) vs 87 (34.4%); p = 0.021) and CR-POPF (13 (18.3%) vs 10 (3.9%); p < 0.001) were more frequent in Group B. CONCLUSIONS: In patients with POD1 DFA ≤ 5000, POD3 DFA ≤ 350 may be a practical test to guide safe early drain removal. Further prospective testing may be useful

Tolerance to ToLCNDV in Cucurbita spp

[EN] Tomato leaf curl New Delhi virus (ToLCNDV) is a bipartite begomovirus (Geminiviridae) firstly reported in India and neighboring countries. A severe outbreak of ToLCNDV in Zucchini (Cucurbita pepo) occurred in southern Spain in 2012. Mechanical inoculation and natural infection with Bemisia tabaci, in Almeria, were used to screen part of the COMAV's Cucurbita core collection. The tolerance was assessed by symptomatology and by a PCR-based diagnostic method that allows the detection of the two viral components in a single reaction. Mechanical transmission of ToLCNDV was confirmed in all the species. Severe symptoms were found 30 and 35 days after mechanical and natural inoculation, respectively, in C. pepo, in all accessions belonging to the Zucchini morphotype and to other morphotypes of the subsp. pepo, subsp. ovifera and even in the wild relative C. fraterna. Cucurbita maxima and C. ficifolia were also highly susceptible. The only species showing tolerance was C. moschata. Instead of curling, which was typically observed in most Cucurbita species, in C. moschata we observed mosaic and mottling, which suggest a differential response of this species. Under natural infection, a few C. moschata accessions remained asymptomatic and no virus was detected in the plant apex. Under mechanical inoculation, ToLCNDV symptoms were mild and delayed in these accessions and they were PCR positive. Some of the more tolerant accessions came from India.This work was supported by Project E_RTAE2013-00020-C04-03 from the Spanish Instituto Nacional de Investigaciones Agrarias (INIA) cofunded with FEDER funds.Sáez-Sánchez, C.; Martínez-Martínez, C.; Ferriol Molina, M.; Manzano, S.; Jamilena, M.; López Del Rincón, C.; Picó Sirvent, MB. (2017). Tolerance to ToLCNDV in Cucurbita spp. Acta Horticulturae. (1151):31-35. https://doi.org/10.17660/ActaHortic.2017.1151.6S3135115

Resistance to Tomato leaf curl New Delhi virus in Cucurbita spp

[EN] Tomato leaf curl New Delhi virus (ToLCNDV) is a bipartite begomovirus (family Geminiviridae) first reported in India and its neighbouring countries. ToLCNDV severely affects zucchini crop (Cucurbita pepo) in the main production areas of Southern Spain since 2012. This emerging begomovirus is a serious threat to this and other cucurbit crops. Breeding resistant cultivars is the most promising method for disease control, but requires the identification of sources of resistance in the Cucurbita genus. In this work, we screened for ToLCNDV resistance a large collection of Cucurbita spp. accessions, including landraces and commercial cultivars of the main cultivated species, C. pepo, Cucurbita moschata and Cucurbita maxima and wild species. The screening was performed using mechanical and whitefly inoculation. The level of resistance was assessed by scoring symptom severity and bymeasuring the virus content with quantitative polymerase chain reaction in selected genotypes. Diversity in the response was observed within and among species. Severe symptoms and high viral amounts were found at 30 days after mechanical and whitefly inoculation in C. pepo, in all accessions belonging to the Zucchini morphotype and to other morphotypes of both subspecies, pepo and ovifera, and even in the wild relative Cucurbita fraterna. C. maxima was also highly susceptible. This species showed characteristic symptoms of leaf decay and intense yellowing, different from those of mosaic, curling and internode shortening found in C. pepo. The only species showing resistance was C. moschata. Four accessions were symptomless or had some plants with only mild symptoms after three independent rounds of mechanical inoculation with different inoculum sources. Two of them also remained symptomless after virus inoculation with viruliferous whiteflies. ToLCNDV was detected in these asymptomatic accessions at 15 and 30 days post inoculation, but viral amounts were much lower than those found in susceptible genotypes, suggesting a high level of resistance. The symptoms in the susceptible accessions of this specieswere also different, with a characteristic leaf mottling, evolving to a severe mosaic. The newly identified C. moschata resistant accessions are good candidates for breeding programmes to avoid the damage caused by ToLCNDV.This work was supported by Projects E_RTAE2013-00020-C04-03 and E-RTA2013-00020-C04-01 from the Spanish Instituto Nacional de Investigaciones Agrarias (INIA) cofunded with FEDER funds.Sáez Sánchez, C.; Martínez Martínez, C.; Ferriol Molina, M.; Manzano, S.; Velasco, L.; Jamilena, M.; López Del Rincón, C.... (2016). Resistance to Tomato leaf curl New Delhi virus in Cucurbita spp. ANNALS OF APPLIED BIOLOGY. 169(1):91-105. https://doi.org/10.1111/aab.12283S91105169

Revisión bibliográfica de implantología bucofacial del año 2009. 2ª parte

Debido al amplio número de publicaciones que existen sobre Implantología Bucofacial, resulta difícil para el odontólogo seleccionar y leer de forma crítica una cantidad suficiente de artículos que puedan aportarle una información útil para su praxis diaria. En este artículo pretendemos sintetizar la información más relevante que se encuentra en las revistas indexadas de la especialidad publicadas el año 2009

Revisión bibliográfica de implantología bucofacial del año 2009. 2ª parte

Debido al amplio número de publicaciones que existen sobre Implantología Bucofacial, resulta difícil para el odontólogo seleccionar y leer de forma crítica una cantidad suficiente de artículos que puedan aportarle una información útil para su praxis diaria. En este artículo pretendemos sintetizar la información más relevante que se encuentra en las revistas indexadas de la especialidad publicadas el año 2009