Modeling the Fate and Transport of Malathion in the Pagsanjan-Lumban Basin, Philippines

Exposure to highly toxic pesticides could potentially cause cancer and disrupt the development of vital systems. Monitoring activities were performed to assess the level of contamination; however, these were costly, laborious, and short-term leading to insufficient monitoring data. However, the performance of the existing Soil and Water Assessment Tool (SWAT model) can be restricted by its two-phase partitioning approach, which is inadequate when it comes to simulating pesticides with limited dataset. This study developed a modified SWAT pesticide model to address these challenges. The modified model considered the three-phase partitioning model that classifies the pesticide into three forms: dissolved, particle-bound, and dissolved organic carbon (DOC)-associated pesticide. The addition of DOC-associated pesticide particles increases the scope of the pesticide model by also considering the adherence of pesticides to the organic carbon in the soil. The modified SWAT and original SWAT pesticide model was applied to the Pagsanjan-Lumban (PL) basin, a highly agricultural region. Malathion was chosen as the target pesticide since it is commonly used in the basin. The pesticide models simulated the fate and transport of malathion in the PL basin and showed the temporal pattern of selected subbasins. The sensitivity analyses revealed that application efficiency and settling velocity were the most sensitive parameters for the original and modified SWAT model, respectively. Degradation of particulate-phase malathion were also significant to both models. The rate of determination (R2) and Nash-Sutcliffe efficiency (NSE) values showed that the modified model (R2 = 0.52; NSE = 0.36) gave a slightly better performance compared to the original (R2 = 0.39; NSE = 0.18). Results from this study will be able to aid the government and private agriculture sectors to have an in-depth understanding in managing pesticide usage in agricultural watersheds

Changes in Oral Vowel Sounds and Hyoid Bone Movement After Thyroidectomy

Objectives Voice and speech alterations after total thyroidectomy may be associated with other extralaryngeal factors, such as neck muscle dysfunction and neck scar contracture. We evaluated the acoustic characteristics of oral vowel sounds and changes in hyoid bone movement before and after thyroidectomy. Methods Twenty-nine female patients undergoing total thyroidectomy were included. Fundamental frequencies (Fo), formants and vowel space areas were evaluated before surgery and 7 days and 3 months after surgery to acoustically analyze the oral vowel sounds. Videofluoroscopic images were taken at the same times to evaluate hyoid bone movement. Results The Fo levels of seven vowels decreased significantly after surgery. The vowel formant changes the F1 of vowel /[e]/ decreased significantly from baseline at 3 months postoperatively, and the F3 of vowel /[i]/ decreased significantly from baseline 7 days postoperatively. The change in the vowel space area was not observed. The Y coordinate of the vowels /[i]/ and /[e]/ decreased significantly from baseline 7 days postoperatively due to changes in hyoid movement. Conclusion The damage to the neck muscles after thyroidectomy changes in Fo, formant and hyoid bone position. These quantitative results could be used as basic data for voice management in patients who undergo thyroidectomy

High-yield exfoliation of three-dimensional graphite into two-dimensional graphene-like sheets

Edge-functionalized graphite (EFG) is prepared via a "direct'' covalent attachment of organic molecular wedges. The EFG is dispersed in N-methyl-2-pyrrolidone with a concentration as high as 0.27 mg mL(-1), leading to high-yield exfoliation of the three-dimensional graphite into two-dimensional graphene-like sheets.close464

Monolithically Integratable Colliding Pulse Modelocked Laser Source for O-CDMA Photonic Chip Development

We demonstrate modelocking of a colliding-pulse mode-locked laser formed by 3-μm-deep etched-mirrors on an InP platform for integration with passive waveguide components. Timing jitter of 243 fs and pulse width of 10 ps were measured

Monolithically Integratable Colliding Pulse Modelocked Laser Source for O-CDMA Photonic Chip Development

We demonstrate modelocking of a colliding-pulse mode-locked laser formed by 3-μm-deep etched-mirrors on an InP platform for integration with passive waveguide components. Timing jitter of 243 fs and pulse width of 10 ps were measured

Optical-CDMA in InP

This paper describes the InP platforms for photonic integration and the development on these platforms of an optical code division multiple access (O-CDMA) system for local area networks. We demonstrate three building blocks of this system: an optical pulse source, an encoder/decoder pair, and a threshold detector. The optical pulse source consists of an integrated colliding pulse-mode laser with nearly transform-limited 10 Gb/s pulses and optical injection locking to an external clock for synchronization. The encoder/decoder pair is based on arrayed waveguide gratings. Bit-error-rate measurements involving six users at 10 Gb/s showed error-free transmission, while O-CDMA codes were calibrated using frequency resolved optical gating. For threshold detection after the decoder, we compared two Mach--Zehnder interferometer (MZI)-based optical thresholding schemes and present results on a new type of electroabsorber-based MZI