Taxonomic composition and growth rates of phytoplankton assemblages at the Subtropical Convergence east of New Zealand

Off the eastern coast of New Zealand, warm, saline, nutrient-poor Subtropical Waters (STW) are separated from. cool, fresher, relatively nutrient-rich Sub-Antarctic Waters (SAW) by the Subtropical Convergence (STC). The Chatham Rise, a submarine rise, restricts. the latitudinal movement of the STC as well as mixing of STW and SAW Due to this restriction, this sector of the STC is characterized by sharp gradients in temperature, macro-(nitrate, silicate and phosphate) and micro- (iron) nutrient concentrations. Shipboard incubations were conducted during austral spring 2000 and 2001 to test the hypothesis that these gradients affect the taxonomic composition and/or growth rates of phytoplankton on either side of and at the STC. Maximum chlorophyll a concentrations during 2000 were 0.39 mu g L-1 but were an order of magnitude higher in 2001. During both years, STC phytoplankton were dominated by diatoms (77% of the to a chlorophyll a during austral spring 2000 and 70% during spring 2001), whereas crytopytes and prasinopytes dominated STW,assemblages (27 and 36% during 2000, and 63 and 17% during 2001). Chlorophyll in the SAW was dominated by procaryotes and photosynthetic nanoflagellates during 2000 (17% procaryotes. 68% nanoflagellates), and by diatoms during the austral spring 2001 cruise (53%). Growth rates of the phytoplankton assemblage were determined by C-14-labeling of chlorophyll a and photosynthetic pigments. During 2000, temperature-normalized growth rates were near maximal ai the STC, and decreased on average to less than half of the maximum north and south of that front, whereas in 2001 both absolute and relative growth rates were low at all stations. Growth rates did not closely parallel biomass of the various taxa, suggesting that nutrient limitation and/or grazing were significantly impacting standing stocks. It appeared that growth was strongly influenced by nutrients and light, but that biomass was more strongly influenced by grazing The STC is a globally important region of enhanced biomass and productivity; however, the phytoplankton assemblage reflects control by both top-down and bottom-up processes that makes a predictive understanding of the area\u27s biogeochemical cycles extremely difficult

Temporal progression of photosynthetic-strategy in phytoplankton in the Ross Sea, Antarctica

The bioavailability of iron influences the distribution, biomass and pioductivity of phytoplankton in the Ross Sea, one of the most productive regions in the Southern Ocean. We mapped the spatial and temporal extent and severity of iron-limitation of the native phytoplankton assemblage using long- (\u3e24 h) and short-term (24 h) iron-addition experiments along with physiological and molecular characterisations during a cruise to the Ross Sea in December February 2012. Phytoplankton increased their photosynthetic efficiency in response to iron addition, suggesting proximal iron limitation throughout most of the Ross Sea during summer. Molecular and physiological data further indicate that as nitrate is removed from the surface ocean the phytoplankton community transitions to one displaying an iron-efficient photosynthetic strategy characterised by an increase in the size of photosystem II (PSII) photochemical cross section (sigma(rpsII)) and a decrease in the chlorophyll-normalised PSII abundance. These results suggest that phytoplankton with the ability to reduce their photosynthetic iron requirements are selected as the growing season progresses, which may drive the well-documented progression from Phaeocystis antarctica- assemblages to diatom-dominated phytoplanlcton. Such a shift in the assemblage-level photosynthetic strategy potentially mediates further drawdown of nitrate following the development of iron deficient conditions in the Ross Sea

ATTITUDE TOWARDS PHYSICAL EDUCATION COURSES AND ACADEMIC PERFORMANCE OF SOPHOMORE STUDENTS IN A STATE UNIVERSITY

The purpose of this study was to ascertain the attitude and academic performance in Physical Education courses of sophomore students in the College of Teacher Education at Batangas State University- JPLPC Campus, for the academic year 2013- 2014. It sought to investigate further the following main problems: What is the attitude of the student towards Physical Education courses in terms of movement, fitness management, safety, personal and social management and healthy lifestyle practices? How may the academic performance of the respondents be described? Is there a significant relationship between the attitude of the respondents and their academic performance in Physical Education? What is the implication of the findings of this study to Physical Education instruction?This study was guided by the null hypothesis which stated that there was no significant relationship between the attitudes of the respondents in terms of movement, fitness management, personal and social management and healthy lifestyle practices, and their academic performance in Physical Education.The researchers applied the descriptive correlational method of research. The principal tool in gathering the data was the questionnaire prepared by the researchers. The study employed the frequency and percentage, weighted mean, Pearson’s r and Chi Square formula.After the careful tabulation, statistical treatment, analysis and interpretation of data, the following findings are revealed: the composite mean of 3.28, 3.43, 3.49, 3.25, 3.32 reflects a highly positive attitude among the respondents in terms of Movement, Fitness Management, Safety, Personal and Social Management, and Healthy and Lifestyle Practices respectively.Considering the significant findings revealed and conclusions drawn in this study, the researchers suggested the following recommendations: Enrichment activities were suggested to improve the attitude of the respondents in the areas of Physical Education Movement, Fitness Management, Safety, Personal and Social Management and Healthy Lifestyle Practices

Efficacy of Tree Leaves as Bioindicator to Assess Air Pollution Based on Using Composite Proxy Measure

Air pollution has become a major issue in cities due to urbanization, population growth, industrial development, and increasing number of vehicles. The study used Gmelina arborea tree leaves as a bioindicator to determine the Air Pollution Tolerance Index (APTI) as a simple and effective compositional index of environmental health in three cities in the Caraga Region, Philippines. To calculate the APTI, four biochemical parameters of tree leaves were calculated: relative water content, total chlorophyll content, leaf-extract pH, and ascorbic acid content. In terms of the APTI category, results showed that all G. arborea species collected in all sample sites are classified as sensitive to air pollution, with the sample collected in Bayugan City being the most sensitive, with an APTI value of 7.66, and the samples collected in Butuan and Cabadbaran City being the least sensitive, with APTI values of 9.54 and 9.11, respectively. A Kruskal-Wallis test revealed a significant difference between the APTI values of G. arborea trees in the three sampling areas in the Caraga region. Based on the APTI computed values of the tree leaves determined in all sites, it is concluded that G. arborea species can be used as a bioindicator of air pollution, classified as sensitive