Contrasting seasonality in optical-biogeochemical properties of the Baltic Sea

Optical-biogeochemical relationships of particulate and dissolved organic matter are presented in support of remote sensing of the Baltic Sea pelagic. This system exhibits strong seasonality in phytoplankton community composition and wide gradients of chromophoric dissolved organic matter (CDOM), properties which are poorly handled by existing remote sensing algorithms. Absorption and scattering properties of particulate matter reflected the seasonality in biological (phytoplankton succession) and physical (thermal stratification) processes. Inherent optical properties showed much wider variability when normalized to the chlorophyll-a concentration compared to normalization to either total suspended matter dry weight or particulate organic carbon. The particle population had the largest optical variability in summer and was dominated by organic matter in both seasons. The geographic variability of CDOM and relationships with dissolved organic carbon (DOC) are also presented. CDOM dominated light absorption at blue wavelengths, contributing 81% (median) of the absorption by all water constituents at 400 nm and 63% at 442 nm. Consequentially, 90% of water-leaving radiance at 412 nm originated from a layer (z90) no deeper than approximately 1.0 m. With water increasingly attenuating light at longer wavelengths, a green peak in light penetration and reflectance is always present in these waters, with z90 up to 3.0–3.5 m depth, whereas z90 only exceeds 5 m at biomass < 5 mg Chla m-3. High absorption combined with a weakly scattering particle population (despite median phytoplankton biomass of 14.1 and 4.3 mg Chla m-3 in spring and summer samples, respectively), characterize this sea as a dark water body for which dedicated or exceptionally robust remote sensing techniques are required. Seasonal and regional optical-biogeochemical models, data distributions, and an extensive set of simulated remote-sensing reflectance spectra for testing of remote sensing algorithms are provided as supplementary data

Loadings of dissolved organic matter and nutrients from the Neva River into the Gulf of Finland – Biogeochemical composition and spatial distribution within the salinity gradient

We studied the loadings of dissolved organic matter (DOM) and nutrients from the Neva River into the Eastern Gulf of Finland, as well as their distribution within the salinity gradient. Concentrations of dissolved organic carbon (DOC) ranged from 390 to 840 μM, and were related to absorption of colored DOM (CDOM) at 350 nm, aCDOM(350), ranging from 2.70 to 17.8 m-1. With increasing salinity both DOC and aCDOM decreased, whereas the slope of aCDOM spectra, SCDOM(300-700), ranging from 14.3 to 21.2 μm-1, increased with salinity

Basin-scale spatio-temporal variability and control of phytoplankton photosynthesis in the Baltic Sea: The first multiwavelength fast repetition rate fluorescence study operated on a ship-of-opportunity

This study presents the results of the first field application of a flow-through multi-wavelength Fast Repetition Rate fluorometer (FRRF) equipped with two excitation channels (458 and 593 nm). This device aims to improve the measurement of mixed cyanobacteria and algae community's photosynthetic parameters and was designed to be easily incorporated into existing ferrybox systems. We present a spatiotemporal analysis of the maximum photochemical efficiency (Fv/Fm) and functional absorption cross section (σPSII) recorded from April to August 2014 on a ship-of-opportunity commuting twice per week between Helsinki (Finland) and Travemünde (Germany). Temporal variations of Fv/Fm and σPSII differed between areas of the Baltic Sea. However, even though the Baltic Sea is characterized by several physico-chemical gradients, no gradient was observed in Fv/Fm and σPSII spatial distribution suggesting complex interactions between biotic and abiotic controls. σPSII was sensitive to phytoplankton seasonal succession and thus differed according to the wavelength used to excite photosystems II (PSII) pigments. This was particularly true in summer when high σPSII(593) values were observed later and longer than high σPSII(458) values, reflecting the role of cyanobacteria in photosynthetic light uptake measured at community scale. In contrast, Fv/Fm variations were similar after excitation at 458 nm or 593 nm suggesting that the adjustment of Fv/Fm in response to environmental factors was similar for the different groups (algae vs. cyanobacteria) present within the phytoplankton community

Yhtenäiset vaatimukset lääketieteen ja hammaslääketieteen tohtorintutkinnolle Suomessa

Oulussa järjestettiin 13.6.2018 lääketieteen ja hammaslääketieteen tohtorintutkinnon konsensuskokous, jossa käytiin läpi vallitsevia käytäntöjä ja muutostarpeita. Ohjeellinen tutkinnon laajuus on neljä vuotta kokopäiväistä työtä, ja muodollisesti tutkinnon myöntää yhtä yliopistoa lukuun ottamatta aina vastaava tiedekunta. Ohjaajia on tyypillisesti kahdesta kolmeen, ja yksi on pääohjaaja. Seurantaryhmä on käytössä tai ollaan ottamassa käyttöön kaikissa yliopistoissa. Aktiivinen seurantaryhmä tukee merkittävästi ohjausprosessia. Väitöskirjojen asiantuntijoina toimivat esitarkastajat ja vastaväittäjät ovat yleensä muualta kuin suorituspaikan yliopistosta. Osittain tästä syystä suuria eroja eri yliopistojen tohtorintutkinnon vaatimusten välillä ei todettu. Haasteena väitöskirjatyössä on kliinisen työn paine ja nuorten kollegoiden ruuhkavuosien kuormittuminen, mitkä heikentävät mahdollisuuksia tutkimustyöhön. Myönteisiä muutoksia ovat olleet tohtoriopintojen systematisoituminen sekä ohjaamisen tason ja väitöskirjantekijöiden tuen paraneminen. Kaikki osallistuneet kannattivat käytäntöjen vakiinnuttamista ja yhtenäistämistä säännöllisellä konsensuskokoustyöskentelyllä.</p

Cigarette smoking and tooth loss experience among young adults: a national record linkage study

<p>Abstract</p> <p>Background</p> <p>Various factors affect tooth loss in older age including cigarette smoking; however, evidence regarding the association between smoking and tooth loss during young adulthood is limited. The present study examined the association between cigarette smoking and tooth loss experience among adults aged 20–39 years using linked data from two national databases in Japan.</p> <p>Methods</p> <p>Two databases of the National Nutrition Survey (NNS) and the Survey of Dental Diseases (SDD), which were conducted in 1999, were obtained from the Ministry of Health, Labor and Welfare with permission for analytical use. In the NNS, participants received physical examinations and were interviewed regarding dietary intake and health practices including cigarette smoking, whereas in the SDD, participants were asked about their frequency of daily brushing, and received oral examinations by certified dentists. Among 6,805 records electronically linked via household identification code, 1314 records of individuals aged 20 to 39 years were analyzed. The prevalence of 1+ tooth loss was compared among non-, former, and current smokers. Multiple logistic regression models were constructed including confounders: frequency of tooth brushing, body mass index, alcohol consumption, and intake of vitamins C and E.</p> <p>Results</p> <p>Smoking rates differed greatly in men (53.3%) and women (15.5%). The overall prevalence of tooth loss was 31.4% (31.8% men and 31.1% women). Tooth loss occurred more frequently among current smokers (40.6%) than former (23.1%) and non-smokers (27.9%). Current smoking showed a significant association with 1+ tooth loss in men (adjusted OR = 2.21 [1.40–3.50], P = 0.0007) and women (1.70 [1.13–2.55], P = 0.0111). A significant positive exposure-related relationship between cigarette smoking status and tooth loss was observed (P for trend < 0.0001 and 0.0004 in men and women, respectively). Current smoking was also associated with the prevalence of decayed teeth (1.67 [1.28–2.20], P = 0.0002).</p> <p>Conclusion</p> <p>An association between cigarette smoking and tooth loss was evident among young adults throughout Japan. Due to limitations of the available variables in the present databases, further studies including caries experience and its confounders should be conducted to examine whether smoking is a true risk of premature tooth loss in young adults.</p

Self-reported dental hygiene, obesity, and systemic inflammation in a pediatric rural community cohort

Background A growing body of epidemiologic evidence links oral health, obesity, and cardiovascular health, though few studies have reported on these relationships in children. While underlying mechanisms are unclear, adult studies have suggested sub-acute systemic inflammation, also implicated in the etiology of both obesity and cardiovascular disease. This study investigated associations between self-reported dental hygiene, obesity, and systemic inflammation in children. Methods 128 children \u3c 19 years of age from rural counties in West Virginia participated in a community-based health screening that included anthropometric assessments, blood collection, and a questionnaire about dental hygiene and self-assessed oral health. Results Participants ranged from 3.0-18.7 years. Univariate analysis demonstrated an association between parent-reported dental hygiene, including frequency of preventive dental care and parent-assessed overall dental health, and markers of systemic inflammation but not obesity. In multivariable regression, parent-assessed overall dental health and obesity were independent predictors of systemic inflammation, after adjustment for age, gender, and parent education. Conclusions This is the first known study of the association between dental hygiene, obesity, and systemic inflammation in children. These results highlight the importance of preventive dental care in overall, systemic health in children and are consistent with previous reports in adults

Maternal oral health status and preterm low birth weight at Muhimbili National Hospital, Tanzania: a case-control study

The study examined the relationship between oral health status (periodontal disease and carious pulpal exposure (CPE)) and preterm low-birth-weight (PTLBW) infant deliveries among Tanzanian-African mothers at Muhimbili National Hospital (MNH), Tanzania. A retrospective case-control study was conducted, involving 373 postpartum mothers aged 14-44 years (PTLBW--150 cases) and at term normal-birth-weight (TNBW)--223 controls), using structured questionnaire and full-mouth examination for periodontal and dentition status. The mean number of sites with gingival bleeding was higher in PTLBW than in TNBW (P = 0.026). No significant differences were observed for sites with plaque, calculus, teeth with decay, missing, filling (DMFT) between PTLBW and TNBW. Controlling for known risk factors in all post-partum (n = 373), and primiparaous (n = 206) mothers, no significant differences were found regarding periodontal disease diagnosis threshold (PDT) (four sites or more that had probing periodontal pocket depth 4+mm and gingival bleeding > or = 30% sites), and CPE between cases and controls. Significant risk factors for PTLBW among primi- and multiparous mothers together were age < or = 19 years (adjusted Odds Ratio (aOR) = 2.09, 95% Confidence interval (95% CI): 1.18-3.67, P = 0.011), hypertension (aOR = 2.44, (95% CI): 1.20-4.93, P = 0.013) and being un-married (aOR = 1.59, (95% CI): 1.00-2.53, P = 0.049). For primiparous mothers significant risk factors for PTLBW were age < or = 19 years (aOR = 2.07, 95% CI: 1.13 - 3.81, P = 0.019), and being un-married (aOR = 2.58, 95% CI: 1.42-4.67, P = 0.002). These clinical findings show no evidence for periodontal disease or carious pulpal exposure being significant risk factors in PTLBW infant delivery among Tanzanian-Africans mothers at MNH, except for young age, hypertension, and being unmarried. Further research incorporating periodontal pathogens is recommended

Predicting the Electron Requirement for Carbon Fixation in Seas and Oceans

Marine phytoplankton account for about 50% of all global net primary productivity (NPP). Active fluorometry, mainly Fast Repetition Rate fluorometry (FRRf), has been advocated as means of providing high resolution estimates of NPP. However, not measuring CO2-fixation directly, FRRf instead provides photosynthetic quantum efficiency estimates from which electron transfer rates (ETR) and ultimately CO2-fixation rates can be derived. Consequently, conversions of ETRs to CO2-fixation requires knowledge of the electron requirement for carbon fixation (Φe,C, ETR/CO2 uptake rate) and its dependence on environmental gradients. Such knowledge is critical for large scale implementation of active fluorescence to better characterise CO2-uptake. Here we examine the variability of experimentally determined Φe,C values in relation to key environmental variables with the aim of developing new working algorithms for the calculation of Φe,C from environmental variables. Coincident FRRf and 14C-uptake and environmental data from 14 studies covering 12 marine regions were analysed via a meta-analytical, non-parametric, multivariate approach. Combining all studies, Φe,C varied between 1.15 and 54.2 mol e- (mol C)-1 with a mean of 10.9±6.91 mol e- mol C)-1. Although variability of Φe,C was related to environmental gradients at global scales, region-specific analyses provided far improved predictive capability. However, use of regional Φe,C algorithms requires objective means of defining regions of interest, which remains challenging. Considering individual studies and specific small-scale regions, temperature, nutrient and light availability were correlated with Φe,C albeit to varying degrees and depending on the study/region and the composition of the extant phytoplankton community. At the level of large biogeographic regions and distinct water masses, Φe,C was related to nutrient availability, chlorophyll, as well as temperature and/or salinity in most regions, while light availability was also important in Baltic Sea and shelf waters. The novel Φe,C algorithms provide a major step forward for widespread fluorometry-based NPP estimates and highlight the need for further studying the natural variability of Φe,C to verify and develop algorithms with improved accuracy. © 2013 Lawrenz et al