Effects of warming and eutrophication on coastal phytoplankton production

Phytoplankton production in coastal waters influences seafood production and human health and can lead to harmful algal blooms. Water temperature and eutrophication are critical factors affecting phytoplankton production, although the combined effects of warming and nutrient changes on phytoplankton production in coastal waters are not well understood. To address this, phytoplankton production changes in natural waters were investigated using samples collected over eight months, and under 64 different initial conditions, established by combining four different water temperatures (i.e., ambient T, + 2, + 4, and + 6 degrees C), and two different nutrient conditions (i.e., non-enriched and enriched). Under the non-enriched conditions, the effect of warming on phytoplankton production was significantly positive in some months, significantly negative in others, or had no effect. However, under enriched conditions, warming affected phytoplankton production positively in all months except one, when the salinity was as low as 6.5. These results suggest that nutrient conditions can alter the effects of warming on phytoplankton production. Of several parameters, the ratio of initial nitrate concentration to chlorophyll a concentration [NCCA, mu M (pg L-1)(-1))] was one of the most critical factors determining the directionality of the warming effects. In laboratory experiments, when NCCA in the ambient or nutrient-enriched waters was >= 1.2, warming increased or did not change phytoplankton production with one exception; however, when NCCA was < 1.2, warming did not change or decreased production. In the time series data obtained from the coastal waters of four target countries, when NCCA was 1.5 or more, warming increased phytoplankton production, whereas when NCCA was lower than 1.5, warming lowered phytoplankton production, Thus, it is suggested that NCCA could be used as an index for predicting future phytoplankton production changes in coastal waters.11Ysciescopu

Mutations at codons 178, 200-129, and 232 contributed to the inherited prion diseases in Korean patients

Background: Polymorphisms of the human prion protein gene (PRNP) contribute to the genetic determinants of Creutzfeldt-Jakob disease (CJD). Numerous polymorphisms in the promoter regions as well as the open reading frame of PRNP were investigated. Greater than 90% of Korean, Chinese, and Japanese carry the homozygote 129 MM codon. In Korea, polymorphisms have not been comprehensively studied, except codons 129 and 219 in PRNP among Korean CJD cases. Although polymorphisms at codons 129 and 219 play an important role in susceptibility to sporadic CJD, patients with other polymorphisms in PRNP exhibited critical distinctions of clinical symptoms. Methods: The genetic analyses of PRNP were carried out among probable CJD patients in comparison with the results from magnetic resonance imaging (MRI) and electroencephalogram (EEG). Results: The molecular analyses revealed that three mutations at codons D178N, E200K, and M232R in heterozygosity. Patients with the D178N and M232R mutations had a 129MM codon, whereas the patient with the E200K mutation showed 129MV heterozygosity. They all revealed strong 14-3-3 positive signals. The 67-year-old patient with the D178N-129M mutation showed progressive gait disturbance and dysarthria was in progress. The 58-year-old patient with the E200K mutation coupled to the 129MV codon had gait disturbance, dysarthria, agitation, and ataxic gait, and progressed rapidly to death 3 months from the first onset of symptoms. The 65-year-old patient with the M232R mutation showed rapidly progressive memory decline and gait disturbance, and died within 16 months after onset of symptoms. Conclusion: Despite differences in ethnicity, the clinical and pathological outcomes were similar to the respective mutations around the world, except absence of insomnia in D178N-129M subject.This research was funded by the Ministry for Health, Welfare and Family Affairs, Korea (grant number, 4800-4835-301-210).Shiga Y, 2007, J NEUROL, V254, P1509, DOI 10.1007/s00415-007-0540-9Kovacs GG, 2005, HUM GENET, V118, P166, DOI 10.1007/s00439-005-0020-1Zarranz JJ, 2005, J NEUROL NEUROSUR PS, V76, P1491, DOI 10.1136/jnnp.2005.056606KONG Q, 2004, PRION BIOL DIS, P673Spacey SD, 2004, ARCH NEUROL-CHICAGO, V61, P122Huang N, 2003, NEUROLOGY, V61, P354Kovacs GG, 2002, J NEUROL, V249, P1567, DOI 10.1007/s00415-002-0896-9Collinge J, 2001, ANNU REV NEUROSCI, V24, P519Schroter A, 2000, ARCH NEUROL-CHICAGO, V57, P1751Wong NKC, 2000, J MOL GRAPH MODEL, V18, P126Taniwaki Y, 2000, J NEUROL NEUROSUR PS, V68, P388Wiltfang J, 1999, J NEUROCHEM, V73, P2485Hainfellner JA, 1999, ANN NEUROL, V45, P812Swietnicki W, 1998, J BIOL CHEM, V273, P31048Riek R, 1998, P NATL ACAD SCI USA, V95, P11667, DOI 10.1073/pnas.95.20.11667Zerr I, 1998, ANN NEUROL, V43, P32ZEIDLER M, 1998, WHO MANUAL STRENGTHERosenmann H, 1997, NEUROLOGY, V49, P593Hoque MZ, 1996, ACTA NEUROPATHOL, V92, P441Nagayama M, 1996, NEUROLOGY, V47, P1313Steinhoff BJ, 1996, ARCH NEUROL-CHICAGO, V53, P162PARCHI P, 1995, CURR OPIN NEUROL, V8, P286BROWN P, 1994, ANN NEUROL, V35, P513PRUSINER SB, 1994, ANN NEUROL, V35, P385GABIZON R, 1994, PHILOS T ROY SOC B, V343, P385HITOSHI S, 1993, J NEUROL SCI, V120, P208GOLDFARB LG, 1992, SCIENCE, V258, P806BROWN P, 1991, EUR J EPIDEMIOL, V7, P469STAHL N, 1990, BIOCHEMISTRY-US, V29, P8879BROWN P, 1986, ANN NEUROL, V20, P597

The newly described heterotrophic dinoflagellate gyrodinium moestrupii, an effective protistan grazer of toxic dinoflagellates

Few protistan grazers feed on toxic dinoflagellates, and low grazing pressure on toxic dinoflagellates allows these dinoflagellates to form red-tide patches. We explored the feeding ecology of the newly described heterotrophic dinoflagellate Gyrodinium moestrupii when it fed on toxic strains of Alexandrium minutum, Alexandrium tamarense, and Karenia brevis and on nontoxic strains of A. tamarense, Prorocentrum minimum, and Scrippsiella trochoidea. Specific growth rates of G. moestrupii feeding on each of these dinoflagellates either increased continuously or became saturated with increasing mean prey concentration. The maximum specific growth rate of G. moestrupii feeding on toxic A. minutum (1.60/d) was higher than that when feeding on nontoxic S. trochoidea (1.50/d) or P. minimum (1.07/d). In addition, the maximum growth rate of G. moestrupii feeding on the toxic strain of A. tamarense (0.68/d) was similar to that when feeding on the nontoxic strain of A. tamarense (0.71/d). Furthermore, the maximum ingestion rate of G. moestrupii on A. minutum (2.6 ng C/grazer/d) was comparable to that of S. trochoidea (3.0 ng C/grazer/d). Additionally, the maximum ingestion rate of G. moestrupii on the toxic strain of A. tamarense (2.1 ng C/grazer/d) was higher than that when feeding on the nontoxic strain of A. tamarense (1.3 ng C/grazer/d). Thus, feeding by G. moestrupii is not suppressed by toxic dinoflagellate prey, suggesting that it is an effective protistan grazer of toxic dinoflagellates.N

A Breast Tumor Classification Method based on Ultrasound BI-RADS Data Mining

Abstract-In this paper, to reduce the response time of computer-aided diagnostic (CAD) systems, we proposed a feature selection algorithm that utilizes BI-RADS which is the standard clinical considerations for radiologists to illustrate the visual characteristics of breast tumors. We first apply the association rule mining technique to the medical database annotated with BI-RADS lexicons by doctors, to find out the interesting BI-RADS lexicon values. Then, we select the image processing algorithms which effectively represent the chosen BI-RADS lexicon values. Finally, the features obtained from the selected image processing algorithms are used to build our classifier using Support Vector Machine (SVM) to predict whether each tumor is benign or malignant. Our experimental result shows that our classifier is accurate with fast execution time

Association of self-reported sedentary time with insulin resistance among Korean adults without diabetes mellitus: a cross-sectional study

Abstract Background A more sedentary lifestyle can result in insulin resistance. However, few research studies have assessed the association between insulin resistance and sedentary lifestyle in Asian populations. Therefore, this study aimed to investigate the association of sedentary time with insulin resistance. In addition, we also investigate the moderate effect of employment status, moderate-to-vigorous physical activity (MVPA), and body mass index (BMI) in this association. Methods Data from 2573 individuals who participated in the 2015 Korean National Health and Nutrition Examination Survey were analyzed. Sedentary time was measured using self-administered questionnaires, and IR data were estimated using the homeostasis model assessment–insulin resistance index (HOMA-IR). Adjusted odds ratio (OR) and 95% confidence intervals (CIs) from a multivariable logistic regression model were generated for all participants. Subgroup analysis was only performed between sedentary time and HOMA-IR stratified by employment status, because moderate effects were not significant in the tests for interaction for MVPA and BMI. For all analyses, the individuals were categorized as having high or normal HOMA-IR values (> 1.6 and ≤ 1.6, respectively). Results A HOMA-IR > 1.6 was observed in 40.3% of the sedentary time Q1 (low) group ( 1.6) (OR = 1.40, 95% CI: 1.060–1.838). However, this association was not significant across the other sedentary time groups. Moreover, participants reporting a high sedentary time and were employed had 1.67 times the odds of having a high IR value (HOMA-IR > 1.6) compared to those who reported having a low sedentary time and were employed (OR = 1.67, 95% CI: 1.184–2.344). In the unemployed participants, sedentary time was not associated with IR. Conclusions High sedentary time (≥10.0 h/day) was associated with elevated HOMA-IR among Korean adults without diabetes mellitus. Furthermore, the association between high sedentary time and HOMA-IR values was more pronounced in the employed population

Mixotrophy in the sand-dwelling dinoflagellate Thecadinium kofoidii

Thecadinium kofoidii is a marine sand-dwelling dinoflagellate that sometimes forms dense blooms. This species was previously thought to be an exclusively autotrophic dinoflagellate, and its mixotrophic ability has not been explored yet. By investigating its ecophysiology, its trophic mode should be revealed. We explored the mixotrophic ability of T. kofoidii by examining its protoplasm under light and transmission electron microscopes with diverse algal prey species. Furthermore, the feeding mechanism of T. kofoidii and prey species on which it feeds were investigated. In addition, the growth and ingestion rates of T. kofoidii as a function of prey concentration were determined when feeding on the benthic cryptophyte Rhodomonas salina. Thecadinium kofoidii was able to feed on R. salina and the dinoflagellate Symbiodinium voratum, which had equivalent spherical diameters (ESDs) ≤ 10.1 µm, while it did not feed on the benthic dinoflagellates Levanderina fissa, Prorocentrum concavum or Ostreopsis cf. ovata, which had ESDs ≥ 15 µm. Thecadinium kofoidii fed on the edible prey cells using the peduncle. The maximum ingestion rate of T. kofoidii on R. salina was 1.3 cells predator−1 d−1. However, feeding on R. salina did not significantly increase the growth rate of T. kofoidii. The low ingestion rate of T. kofoidii on R. salina may have partially resulted in the lack of significant increase in its growth rate due to mixotrophy. The present study discovered predator–prey relationships between T. kofoidii and R. salina and S. voratum, which may change our view of the energy flow and carbon cycling in marine benthic food webs.N

Ingestion of the unicellular cyanobacterium Synechococcus by the mixotrophic red tide ciliate Mesodinium rubrum

We explored phagotrophy of the phototrophic ciliate Mesodinium rubrum on the cyanobacterium Synechococcus. The ingestion and clearance rates of M. rubrum on Synechococcus as a function of prey concentration were measured. In addition, we calculated grazing coefficients by combining the field data on abundance of M. rubrum and co-occurring Synechococcus spp. with laboratory data on ingestion rates. The ingestion rate of M. rubrum on Synechococcus sp. linearly increased with increasing prey concentrations up to approximately 1.9 x 10(6) cells mL(-1), to exhibit sigmoidal saturation at higher concentrations. The maximum ingestion and clearance rates of M. rubrum on Synechococcus were 2.1 cells predator(-1) h(-1) and 4.2 nL predator(-1)h(-1), respectively. The calculated grazing coefficients attributable to M. rubrum on co-occurring Synechococcus spp. reached 0.04 day(-1). M. rubrum could thus sometimes be an effective protistan grazer of Synechococcus in marine planktonic food webs. M. rubrum might also be able to form recurrent and massive blooms in diverse marine environments supported by the unique and complex mixotrophic arrays including phagotrphy on hetrotrophic bacteria and Synecho coccus as well as digestion, kleptoplastidy and karyoklepty after the ingestion of cryptophyte prey.N

Ingestion of the unicellular cyanobacterium Synechococcus by the mixotrophic red tide ciliate Mesodinium rubrum

We explored phagotrophy of the phototrophic ciliate Mesodinium rubrum on the cyanobacterium Synechococcus. The ingestion and clearance rates of M. rubrum on Synechococcus as a function of prey concentration were measured. In addition, we calculated grazing coefficients by combining the field data on abundance of M. rubrum and co-occurring Synechococcus spp. with laboratory data on ingestion rates. The ingestion rate of M. rubrum on Synechococcus sp. linearly increased with increasing prey concentrations up to approximately 1.9 x 10(6) cells mL(-1), to exhibit sigmoidal saturation at higher concentrations. The maximum ingestion and clearance rates of M. rubrum on Synechococcus were 2.1 cells predator(-1) h(-1) and 4.2 nL predator(-1)h(-1), respectively. The calculated grazing coefficients attributable to M. rubrum on co-occurring Synechococcus spp. reached 0.04 day(-1). M. rubrum could thus sometimes be an effective protistan grazer of Synechococcus in marine planktonic food webs. M. rubrum might also be able to form recurrent and massive blooms in diverse marine environments supported by the unique and complex mixotrophic arrays including phagotrphy on hetrotrophic bacteria and Synecho coccus as well as digestion, kleptoplastidy and karyoklepty after the ingestion of cryptophyte prey.N