Spatio-Temporal Distribution and Abundance of Phytoplankton in Manila Bay

Understanding the dynamics and production of phytoplankton may contribute to the elucidation of the status of fishery resources and may be the key for better fisheries management since phytoplankton is at the base of the food chain. The changes and succession of phytoplankton community structure in Manila Bay was studied by conducting hydrobiological survey every other month from January 2012 to November 2015. It was determined from this study that diatoms dominated the phytoplankton composition all throughout the survey period and the total phytoplankton density was generally highest during southwest monsoons. Dinoflagellates and cyanobacteria, on the other hand, were relatively most dense during tradewinds. Although causative species for harmful algal blooms and fish kills were present, only the bloom of red Noctiluca scintillans was observed in January 2014 albeit no harmful implication to consumers was reported. Phytoplankton typically converged in the coasts of the bay, particularly at the eastern portion, but it is noteworthy to say that the sporadic pattern seen maybe attributed to the presence of their predators. The dramatic drop in the phytoplankton densities seem to coincide with the spawning of Sardinella fimbriata and Sardinella gibbosa

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Spatial and diel variaton of tintinnid ciliates in Masinloc-Oyon Bay marine reserve

The present study is the first bay wide assessment of Masinloc-Oyon Bay Marine Reserve using biological and environmental parameters. Tintinnids were collected through vertical and horizontal tow during July 2017. Night~ and day-time collection was conducted to verify the diel characteristic of tintinnid species. Environmental parameters (temperature, salinity, pH, DO, TDS) were measured using YSI 6600 multiparameter. The nine identified tintinnid species in this study are first records in Masinloc-Oyon Bay (MOB). The warm water species Helicostomella longa dominated the tintinnid assemblage during wet season of July (29-33°C). Triplots from multivariate analysis showed that stations (1, 6-7) far from Marine Protected Areas (MPAs) create a different cluster compared with the stations (2-5) within MPAs. Station 1 is inside the power plants outfall and consistently had the lowest abundance and diversity. The power plant thermal discharge has a negative effect on abundance and diversity of tintinnids assemblage. No significant difference was observed between night and day-time abundances using horizontal tow. A significant P-value (.000, P\u3e.05) was recorded between night and day-time abundances using vertical tow. The said initial result suggest that tintinnids deviate from the generalized diel characteristic of zooplankton community. The diel and spatial tintinnid variation in this study presented the uniqueness and diversity of MOBs marine environment. Ecological tools such a tintinnids can be used as a bio-indicator to assess the water masses and water quality of such complex site