Tropical Peatland Hydrology Simulated With a Global Land Surface Model.

Tropical peatlands are among the most carbon-dense ecosystems on Earth, and their water storage dynamics strongly control these carbon stocks. The hydrological functioning of tropical peatlands differs from that of northern peatlands, which has not yet been accounted for in global land surface models (LSMs). Here, we integrated tropical peat-specific hydrology modules into a global LSM for the first time, by utilizing the peatland-specific model structure adaptation (PEATCLSM) of the NASA Catchment Land Surface Model (CLSM). We developed literature-based parameter sets for natural (PEATCLSMTrop,Nat) and drained (PEATCLSMTrop,Drain) tropical peatlands. Simulations with PEATCLSMTrop,Nat were compared against those with the default CLSM version and the northern version of PEATCLSM (PEATCLSMNorth,Nat) with tropical vegetation input. All simulations were forced with global meteorological reanalysis input data for the major tropical peatland regions in Central and South America, the Congo Basin, and Southeast Asia. The evaluation against a unique and extensive data set of in situ water level and eddy covariance-derived evapotranspiration showed an overall improvement in bias and correlation compared to the default CLSM version. Over Southeast Asia, an additional simulation with PEATCLSMTrop,Drain was run to address the large fraction of drained tropical peatlands in this region. PEATCLSMTrop,Drain outperformed CLSM, PEATCLSMNorth,Nat, and PEATCLSMTrop,Nat over drained sites. Despite the overall improvements of PEATCLSMTrop,Nat over CLSM, there are strong differences in performance between the three study regions. We attribute these performance differences to regional differences in accuracy of meteorological forcing data, and differences in peatland hydrologic response that are not yet captured by our model.

Rose-trellis periosteal release in oral mucosal advancement flaps in pigs.

The aims of this study were to find out whether scoring in a rose-trellis pattern improved the stretch of mucoperiosteal flaps more than conventional scoring in the horizontal plane, and to consider its application in the closure of oroantral communications. Sixteen sections of cadaveric porcine buccal mucoperiosteum were removed from the molar region of the maxilla and mandible. A three-sided flap was raised in the subperiosteal plane, excised, and pinned to a cork board with the periosteal side facing upwards. Eight samples were scored in the horizontal plane (control) using lines perpendicular to the line of simulated advancement, and eight in a rose-trellis or criss-cross pattern. Scoring using a rose-trellis pattern yielded a mean increase in stretch of 24.3% (p=0.0003) when compared with the conventional method. Buccal advancement flaps are widely used to close oroantral communications, and scoring of the mucoperiosteum facilitates the stretching of the tissue over the defect. To be successful, defects should be fully closed to prevent contamination, and closure should be tension-free. In this study, scoring in a rose-trellis pattern increased the stretch of the tissue sample more than scoring in the horizontal plane. The rose-trellis technique therefore could aid the effective closure of oroantral communications.

Structural outcomes in the Cleft Care UK study. Part 2: dento-facial outcomes.

OBJECTIVES: To compare facial appearance and dento-alveolar relationship outcomes from the CSAG (1998) and CCUK (2013) studies. SETTING AND SAMPLE POPULATION: Five-year-olds born with non-syndromic unilateral cleft lip and palate. Those in the original CSAG were treated in a dispersed model of care with low-volume operators. Those in CCUK were treated in a more centralized, high-volume operator model. MATERIALS AND METHODS: We compared facial appearance using frontal view photographs (252 CCUK, 239 CSAG) and dental relationships using study models (198 CCUK, 223 CSAG). Facial appearance was scored by a panel of six assessors using a standardized and validated outcome tool. Dento-alveolar relationships were scored by two assessors using the 5-Year-Olds' Index. Ordinal regression was used to compare results between surveys. RESULTS: Excellent or good facial appearance was seen in 36.2% of CCUK compared with 31.9% in CSAG. In CCUK, 21.6% were rated as having poor or very poor facial appearance compared with 27.6% in CSAG. The percentage rated as having excellent or good dento-alveolar relationships was 53.0% in CCUK compared with 29.6% in CSAG. In CCUK, 19.2% were rated as having poor or very poor dento-alveolar relationships compared to 36.3% in CSAG. The odds ratios for improved outcome in CCUK compared to CSAG were 1.43 (95% CI 1.03, 1.97) for facial appearance and 2.29 (95% CI 1.47, 3.55) for dento-alveolar relationships. CONCLUSIONS: Facial and dento-alveolar outcomes were better in CCUK children compared to those in CSAG.

Carbon fluxes from an urban tropical grassland.

Turfgrass covers a large fraction of the urbanized landscape, but the carbon exchange of urban lawns is poorly understood. We used eddy covariance and flux chambers in a grassland field manipulative experiment to quantify the carbon mass balance in a Singapore tropical turfgrass. We also assessed how management and variations in environmental factors influenced CO2 respiration. Standing aboveground turfgrass biomass was 80 gC m(-2), with a mean ecosystem respiration of 7.9 ± 1.1 µmol m(-2) s(-1). The contribution of autotrophic respiration was 49-76% of total ecosystem respiration. Both chamber and eddy covariance measurements suggest the system was in approximate carbon balance. While we did not observe a significant relationship between the respiration rates and soil temperature or moisture, daytime fluxes increased during the rainy interval, indicating strong overall moisture sensitivity. Turfgrass biomass is small, but given its abundance across the urban landscape, it significantly influences diurnal CO2 concentrations.

Genetic and physiological bases for phenological responses to current and predicted climates.

We are now reaching the stage at which specific genetic factors with known physiological effects can be tied directly and quantitatively to variation in phenology. With such a mechanistic understanding, scientists can better predict phenological responses to novel seasonal climates. Using the widespread model species Arabidopsis thaliana, we explore how variation in different genetic pathways can be linked to phenology and life-history variation across geographical regions and seasons. We show that the expression of phenological traits including flowering depends critically on the growth season, and we outline an integrated life-history approach to phenology in which the timing of later life-history events can be contingent on the environmental cues regulating earlier life stages. As flowering time in many plants is determined by the integration of multiple environmentally sensitive gene pathways, the novel combinations of important seasonal cues in projected future climates will alter how phenology responds to variation in the flowering time gene network with important consequences for plant life history. We discuss how phenology models in other systems--both natural and agricultural--could employ a similar framework to explore the potential contribution of genetic variation to the physiological integration of cues determining phenology.

Interception and retention of macroscopic bryophyte fragments by branch substrates in a tropical cloud forest: an experimental and demographic approach.

Although the significance of canopy plant communities to ecosystem function is well documented, the process by which such communities become established in trees remains poorly known. Colonization of tree surfaces by canopy-dwelling plants often begins with the establishment of bryophytes, so the conditions that affect the dispersal of bryophytes in the forest canopy merit study. We assessed success rates of one mechanism of bryophyte propagation, the aerial dispersal of macroscopic fragments, using an experimental approach. We quantified interception and retention of marked fragments released from a 36 cm×36 cm grid 50 cm above branches of saplings and mature trees of the species Ocotea tonduzii in a montane cloud forest in Costa Rica. Only 1% of bryophyte fragments dropped over sapling crowns in this manner were retained for the 6-month duration of the study, while branches in the forest canopy with intact epiphyte loads and branches that had been stripped of their epiphytes retained 24% and 5%, respectively. Our results suggest that larger-diameter branches and the presence of other epiphytes can both improve the retention of bryophyte fragments on canopy branches. Further work will be needed to address the relative roles of other dispersal mechanisms (spores, gemmae, microscopic bryophyte fragments) and the dynamics of growth and establishment of macroscopic bryophyte fragments following their interception.

Effects of plane of nutrition and phenobarbital during the pre-mating period on reproduction in ewes fed differentially during the summer and mated in the fall.

An increased plane of nutrition of ewes before mating (flushing) has been associated with an increased number of lambs per ewe. The following study was done to investigate a possible mechanism for the flushing effect. During the summer, 98 Hampshire and Suffolk ewes grazed pastures with 50 of the ewes supplemented with .45 kg of corn grain X head-1 X d-1. For approximately 12 d before fall mating, each ewe received daily either .45 kg of a corn grain-soybean oil meal mixture, an oral dose of 1 g phenobarbital or no treatment. Liver biopsies were collected from 23 ewes, representing all treatment combinations, 3 d after initiation of pre-mating treatment for determination of concentration of hepatic mixed function oxidase enzymes (MFO). Summer supplementation vs no summer supplementation resulted in ewes with heavier (P less than .05) body weights near mating (75.6 vs 71.1 kg), higher (P less than .01) mating condition scores (3.2 vs 2.9), a greater (P less than .01) number of ovulations (1.99 vs 1.74), but little difference (P greater than .10) in number of lambs born per ewe lambing. Pre-mating treatment with phenobarbital or grain mix resulted in a greater number of ovulations (P less than .01, P less than .10, respectively) than no pre-mating treatment (2.14, 1.85, 1.60; respectively). Ewes given phenobarbital had more (P less than .10) lambs per ewe than ewes given no treatment (1.71 vs 1.40). Both phenobarbital and grain mix resulted in a significant increase in concentration of MFO compared with no treatment.(ABSTRACT TRUNCATED AT 250 WORDS)