Ecological Impacts of a Trait-Mediated Cascade.

Ecologists have generally recognized that trait-mediated indirect interactions (TMIIs) can have important impacts on populations and communities. What is less understood is how and to what degree the interplay of TMIIs would affect community dynamics. In this dissertation I take the study of TMIIs one step further to examine a specific system in which two interacting TMIIs act in concert, significantly regulating consumer-resource dynamics in the system. This system contains two interacting TMIIs. The first one consists of a classic ant-hemipteran mutualism. The aggressive arboreal ant, Azteca sericeasur, through its aggressive behavior and harassment prevents the coccinellid beetle, Azya orbigera, from preying on the hemipteran Coccus viridis. The second TMII occurs when the phorid fly, Pseudacteon lascinosous, a parasitoid of A. sericeasur, induces anti-parasitism behavior of the ant. Since the phorid fly needs movement to attack the ant, the ant adopts a motionless posture when the phorid is present, effectively cancelling the first TMII. This ecological system is found in the coffee agroecosystem of the Neotropics and has important implications for pest management. Through a literature review, field surveys, and laboratory experiments I document the effects of these interacting TMIIs on the coccinellid beetle, an important predator of scale insects in coffee. More specifically, my study suggests that the effects of a remote species that never directly interacts with organisms on lateral food chains can significantly affect several demographic parameters of the coccinellid beetle. It influences oviposition, parasitism and sex ratio, each of which is critical to population dynamics. The study also documents the effect of the interacting TMIIs on the general arthropod community that uses coffee. My study also suggests that the specific TMIIs interactions can have a broad community-wide impact.PhDNatural Resources and EnvironmentUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/116676/1/hhsieh_1.pd

Trait-Mediated Indirect Effects of Phorid Flies on Ants

This paper provides a synthesis of the ecological impact of phorid fly parasitoids on ants. We find the most important impact of phorids on ants to be trait-mediated effects. Phorids diminish the foraging activity of ants, frequently reducing the number and average size of foragers and reducing the amount of food retrieved by a colony. However, ants' coping mechanisms include changing foraging site and time. Phorids can also affect competition, especially through changes in the ability of the host to win in exploitative competition. Factors such as microclimate, resource size, and habitat complexity interact with phorids to change their effect on competition. By being highly specific and attacking ants high in the competitive hierarchy, phorids can alter the linear nature of the competitive transitivity, and by reducing the number of foragers, they can change the discovery-dominance tradeoff that is observed in some ant communities. Trait-mediated effects of phorids also cascade to other trophic levels. As an example, we discuss the trait-mediated cascade of phorids on the Azteca instabilis system in coffee. In this system, by reducing the foraging activity of A. instabilis, phorids reduce the direct and indirect biological control impact of the ant in the coffee agroecosystem

NERVE CONDUCTION VELOCITY INVESTIGATION IN ATHLETES WITH TRAINED LOWER EXTRAMITY FOR WELL·CONTROLLlNG MOVEMENT

Reaction, coordination and speed ability are essential for success in a variety of sports. Nerve conduction velocity (NCV) is related to all of these abilities. Previous studies had investigated power and endurance type athletes, but there is less research in athletes who are skilled in coordinated lower extremity movements requiring more neural adaptation for nerve conduction velocity after specific exercise training. The purpose of this study is to investigate nerve conduction velocity of soccer, sanshou players and untrained subjects. Results show that NCV was significantly different among the 3 groups (p < .05) for the femoral and tibal nerves. For both femoral and tibial nerve.§, results showed that the soccer players had significantly faster NCV than the other groups (p < .05). According to the results, faster NCV adaptation from long term training in soccer players may be relate to their movement requirement of changing their movement direction quickly and skillfully

Landslide Potential Evaluation Using Fragility Curve Model

The geological environment of Taiwan mainly contains steep topography and geologically fragile ground surface. Therefore, the vulnerable environmental conditions are prone to landslides during torrential rainfalls and typhoons. The rainfall-induced shallow landslide has become more common in Taiwan due to the extreme weathers in recent years. To evaluate the potential of landslide and its impacts, an evaluation method using the historical rainfall data (the hazard factor) and the temporal characteristics of landslide fragility curve (LFC, the vulnerability factor) was developed and described in this chapter. The LFC model was based on the geomorphological and vegetation factors using landslides at the Chen-Yu-Lan watershed in Taiwan, during events of Typhoon Sinlaku (September 2009) and Typhoon Morakot (August 2009). The critical hazard potential (Hc) and critical fragility potential (Fc) were introduced to express the probability of exceeding a damage state of landslides under certain conditions of rainfall intensity and accumulated rainfall. Case studies at Shenmu village in Taiwan were applied to illustrate the proposed method of landslide potential assessment and the landslide warning in practice. Finally, the proposed risk assessment for landslides can be implemented in the disaster response system and be extended to take debris flows into consideration altogether

POOR FORCE CONTROL PERFORMANCE AND UNVARIED EMG PATTERN AFTER AGONIST MUSCLE FATIGUE IN HUMANS

Ballistic and accurately control of a targeted fast contraction relies on phasic activations of the agonist and antagonist muscles. The purpose of the study was to investigate the effect of tibialis anterior (TA) fatigue on the systematic bias and the consistence of the net dorsiflexion torque generation and the controlling pattern of the agonist-antagonist muscles. Ten subjects were tested twice with a week apart. Fast and slow dorsiflexion at 40%-MVG were measured before and after fatigue of the TA by voluntary isometric dorsiflexions. The EMG of the TA and soleus (Sol) were recorded. The results revealed that more post-fatigue increment of the systematic error was in the fast dorsiflexions, random error increment were similar in both speeds of isometric dorsiflexions, the cocontraction ratio increased after fatigue only in the slow dorsiflexions. Our results suggested that precision of the fast targeted isometric contractions was reduced after fatigue because of unvaried agonist-antagonist control strategy

Generation of heralded optical `Schroedinger cat' states by photon-addition

Optical "Schr\"odinger cat" states, the non-classical superposition of two quasi-classical coherent states, serve as a basis for gedanken experiments testing quantum physics on mesoscopic scales and are increasingly recognized as a resource for quantum information processing. Here, we report the first experimental realization of optical "Schr\"odinger cats" by adding a photon to a squeezed vacuum state, so far only photon-subtraction protocols have been realized. Photon-addition gives us the advantage of using heralded signal photons as experimental triggers, and we can generate "Schr\"odinger cats" at rates exceeding $8.5 \times 10^4$ counts per second; at least one order of magnitude higher than all previously reported realizations. Wigner distributions with pronounced negative parts are demonstrated at down to -8.89 dB squeezing, even when the initial squeezed vacuum input state has low purity. Benchmarking against such a degraded squeezed input state we report a maximum fidelity of more than 80% with a maximum cat amplitude of $|\alpha| \approx 1.66$. Our experiment uses photon-addition from pairs, one of those photons is used for monitoring, giving us enhanced control; moreover the pair production rates are high and should allow for repeated application of photon-addition via repeat-stages.Comment: 5 pages, 2 figures, 1 tabl

Soluble Form of Receptor for Advanced Glycation End Products Is Associated with Obesity and Metabolic Syndrome in Adolescents

The aim of this cross-sectional study was to investigate the relationship between soluble form of receptor for advanced glycation end products (sRAGE), obesity, and metabolic syndrome (MetS) in adolescents. A total of 522 male and 561 female adolescents were enrolled into the final analyses. Anthropometric parameters, blood pressure, blood biochemistry, fasting insulin, and plasma sRAGE levels were measured. In males, sRAGE was significantly and inversely correlated with waist circumference (WC), body mass index (BMI), systolic blood pressure, triglyceride (TG), low density lipoprotein cholesterol (LDL-C), and homeostasis model assessment-insulin resistance (HOMA-IR). Only WC and BMI were significantly and inversely correlated with sRAGE in females. Using linear regression analysis adjusting for age and gender, significant association was found between sRAGE and WC, BMI, TG, LDL-C, and HOMA-IR in adolescents of either gender (P<0.05). This association was abolished when further adjusting BMI. In addition, sRAGE was significantly and inversely correlated with the increasing number of components of MetS in males (P for trend = 0.006) but not in females (P for trend = 0.422). In conclusion, plasma sRAGE is associated with obesity and MetS among adolescents. BMI may be the most important determinant of sRAGE levels in adolescents

Proteomic profiling reveals α1-antitrypsin, α1-microglobulin, and clusterin as preeclampsia-related serum proteins in pregnant women

AbstractObjectivePreeclampsia is a major cause of mortality in pregnant women but the underlying mechanism remains unclear to date. In this study, we attempted to identify candidate proteins that might be associated with preeclampsia in pregnant women by means of proteomics tools.Materials and methodsDifferentially expressed proteins in serum samples obtained from pregnant women with severe preeclampsia (n = 8) and control participants (n = 8) were identified using two-dimensional gel electrophoresis (2-DE) followed by peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Additional serum samples from 50 normal and 41 pregnant women with severe preeclampsia were analyzed by immunoassay for validation.ResultsTen protein spots were found to be upregulated significantly in women with severe preeclampsia. These protein spots had the peptide mass fingerprints matched to α1-antitrypsin, α1-microglobulin, clusterin, and haptoglobin. Immunoassays in an independent series of serum samples showed that serum α1-antitrypsin, α1-microglobulin, and clusterin levels of severe preeclampsia patients (n = 41) were significantly higher than those in the normal participants (n = 50; α1-antitrypsin 295.95 ± 50.94 mg/dL vs. 259.31 ± 33.90 mg/dL, p = 0.02; α1-microglobulin 0.029 ± 0.004 mg/mL vs. 0.020 ± 0.004 mg/mL, p < 0.0001; clusterin 77.6 ± 16.15 μg/dL vs. 67.6 ± 15.87 μg/dL, p < 0.05).ConclusionIdentification of these proteins by proteomics analysis enables further understanding of the pathophysiology of preeclampsia. Further studies are warranted to investigate the role of these biomarkers in prediction of this disease

The Community Ecology of Herbivore Regulation in an Agroecosystem: Lessons from Complex Systems

AbstractWhether an ecological community is controlled from above or below remains a popular framework that continues generating interesting research questions and takes on especially important meaning in agroecosystems. We describe the regulation from above of three coffee herbivores, a leaf herbivore (the green coffee scale, Coccus viridis), a seed predator (the coffee berry borer, Hypothenemus hampei), and a plant pathogen (the coffee rust disease, caused by Hemelia vastatrix) by various natural enemies, emphasizing the remarkable complexity involved. We emphasize the intersection of this classical question of ecology with the burgeoning field of complex systems, including references to chaos, critical transitions, hysteresis, basin or boundary collision, and spatial self-organization, all aimed at the applied question of pest control in the coffee agroecosystem