3layman'sabstracts.pmd Layman’s Abstracts 1 SCIENCE DILIMAN (JANUARY-JUNE 2018) 30:1, 1-3 LAYMAN’S ABSTRACTS Low-Complexity Physical Layer Security Scheme for Heterogeneous Cellular Networks based on Coord inated Precod ing Design and Artif icial Noise Generation Neil Irwin M. Bernardo and Franz de Leon ISSN 0115-7809 Print / ISSN 2012-0818 Online Heterogeneous Network (HetNet) deployment is a cellular system design approach in which multiple low power access nodes are underlaid in a t r a d i t i o n a l m a c r o - c e l l u l a r n e t w o r k . H e t N e t s a r e a b l e t o p r o v i d e s u b s t a n t i a l i n c r e a s e i n ce l l u l a r c a p a c i t y a n d e n e r g y e f f i c i e n c y t h u s making it a viable solution to meet the demands in the next generation of cellular system, also known as 5G. In this study, we investigated how security can be incorporated into the downlink transmission (i.e. from telecommunications network to mobile phones) of HetNets while still m a i n t a i n i n g t h e i r h i g h ce l l u l a r c a p a c i t y a n d h i g h e n e r g y e f f i c i e n c y proper ties. Our approach is to integrate information security, user data r a t e r e q u i r e m e n t , a n d p o w e r co n s u m p t i o n o f t h e H e t N e t ’s d o w n l i n k transmission into a computationally-tractable convex optimization model. F r o m t h e f o r m u l a t e d m o d e l , w e p r o p o s e a s e c u r i t y t e c h n i q u e w i t h s u b o p t i m a l p e r f o r m a n c e b u t w i t h a c o m p u t a t i o n a l c o m p l e x i t y t h a t i s feasible for real-time implementation. Feed ing Habits of Mobula japanica (Chond richthyes, Mobul idae) in Butuan Bay, Mindanao Island, Phil ippines Shirlamaine Irina G. Masangcay, Ephrime B. Metillo, Ken-Ichi Hayashizaki, Satoru Tamada and Shuhei Nishida We studied the feeding habits of the Spinetail Devil Ray Mobula japanica, l o c a l l y k n ow n a s Pa n t i h a n , f r o m B u t u a n B a y, E a s te r n B o h o l S e a f r o m January to May 2016 using data on its stomach contents, and carbon a n d n i t r o g e n s t a b l e i s o t o p e a n a l y s e s . S m a l l s h r i m p - l i k e k r i l l Pseudeuphausia latifrons, known locally as Alamang, contributed almost 100% to the devil ray’s ingested food. Stable isotope analysis conf irmed the specialized feeding and assimilation of the krill food. This study is the f irst to identify the swarming krill P. latifrons as the major food of the Spinetail Devil Ray in Butuan Bay. Layman’s Abstracts 2 Fucoidan Content in Phil ippine Brown Seaweeds Joemark T. Narsico, Joyce A. Nieva, Alper James G. Alcaraz, Elad io G.M. Anino V, Norchel Corcia F. Gomez and Marco Nemesio E. Montaño The Philippines is home to hundreds of seaweed species that serve as sources of high-value natural products, such as fucoidan. Fucoidan is a s u l f a t e d p o l y s a c c h a r i d e t h a t c a n b e e x t r a c t e d f r o m t h e c e l l w a l l s o f brown seaweeds and is reported to have a wide range of bioactivities for possible medicinal applications. In this study, we assessed Philippine brown seaweeds as sources of fucoidan by determining which species or genera among local brown algae has the highest content of partially p u r i f i e d f u co i d a n a n d w h e r e t h e s e s p ec i e s c a n b e f o u n d w i t h i n t h e country. Fucoidan content from different species of brown seaweeds were determined in f i fty sites across four teen provinces in Nor thern Luzo n ( C a g a y a n , I l o c o s ) , W e s t L u z o n ( P a n g a s i n a n ) , t h e E a s t e r n s e a b o a r d o f L u z o n ( Q u e z o n P r o v i n c e , C a m a r i n e s , S o r s o g o n ) , C e n t r a l a n d E a s t e r n Visayas (Bohol, Cebu, Negros Oriental, Negros Occidental), and Northern M i n d a n a o ( C a m i g u i n , L a n a o d e l N o r t e , M i s a m i s O r i e n t a l , M i s a m i s Occidental). Sargassum spp. , the most abundant in all sites, and Turbinaria o r n a t a, fo u n d o n l y i n 1 1 s i te s , b o t h h a ve s i g n i f i c a n t l y h i g h e r co n te n t compared to the other samples. Similarly, higher content of semi-pure f u c o i d a n w e r e o b s e r v e d i n b r o w n s e a w e e d s f r o m B o h o l , C e b u , Pangasinan, Quezon Province, Camiguin, and Cagayan. Staphylococcus aureus and Methicill in-resistant S. aureus (MRSA) carriage in Publ ic Computer Service Providers and Util ity Jeepneys in UP Dil iman Jann Eldy L. Daquioag, Ricardo Bened ict C. Almirol, Mary Grace B. Ayala, Ma. Socorro Edden P. Subejano and Gil M. Penul iar Staphylococcus aureus is a bacterium that can cause serious infections. I t i s o f t e n f o u n d i n s o l i d o b j e c t s , s u c h a s c o m p u t e r p e r i p h e r a l s o f computer service providers (CSPs) and handrails of public utility jeepneys (PUJs). S. aureus infections are often treated without complications, except Layman’s Abstracts 3 in cases where a particular strain called methicillin-resistant S. aureus (MRSA) is involved. In this study, the prevalence of S. aureus and MRSA in CSPs, computer peripherals, and handrails of PUJs inside UP Diliman, and associated risk factors for contamination were determined. S. aureus a n d M R S A w e r e i d e n t i f i e d u s i n g m o r p h o l o g i c a l , b i o c h e m i c a l , a n d molecular methods from 162 computer peripherals from 27 CSPs, and 196 PUJ handrails. S. aureus was identif ied in 92.6% of CSPs, 36.4% of computer peripherals, and 7.1% of PUJs, whereas MRSA was present in 3.1% of CSPs and 2% of PUJs. No signif icant associations between S. aureus/ M R S A a n d t h e a s s e s s ed r i s k f a c to r s we r e o b s e r ved ( p > 0 . 0 5 ) . Re s u l t s indicate that, while S. aureus prevalence is relatively high, MRSA carriage is low in CSPs and PUJs in UP Diliman. Population Structure of the Krill Prey of the Spinetail Devil Ray Mobula japanica (Chondrichthyes, Mobul idae) from Southeastern Bohol Sea, Phil ippines Shirlamaine Irina G. Masangcay, Ephrime B. Metillo and Shuhei Nishida While investigating the feeding habits of the Spinetail Devil Ray Mobula japonica in Butuan Bay, we found true krill (known locally as Alamang) a s t h e m a i n , oft e n t h e o n l y fo o d i te m i n t h e s to m a c h o f t h e r a y. We identif ied the krill species as Pseudeuphausia latifrons. Information about the population of this krill species is very limited, thus this study was aimed at analyzing the size-composition of individuals collected from the stomach of the ray from January to May 2016. The total lengths of intact krill ranged between 4.0–6.9 mm for juveniles and 7.0–10.9 mm for adults. In general, males were larger than females. Juveniles were dominant until late March, and adults dominated by April and May. The largest male and egg-carrying female individuals also appeared during t h e w a r m m o n t h s of A p r i l a n d M a y, i n d i c a t i n g s p a w n i n g d u r i n g t h e s e months. This study provides evidence that individuals of the krill P. latifrons e a t e n b y r a y s g r o w f r o m j u v e n i l e s t o a d u l t s f r o m J a n u a r y t o M a y i n Butuan Bay.