Leaf trichomes in Metrosideros polymorpha can contribute to avoiding extra water stress by impeding gall formation

Background and Aims: Plants inhabiting arid environments tend to have leaf trichomes, but their adaptive significance remains unclear. Leaf trichomes are known to play a role in plant defence against herbivores, including gall makers. Because gall formation can increase water loss partly through increased surface area, we tested the novel hypothesis that leaf trichomes could contribute to avoiding extra water stress by impeding gall formation, which would have adaptive advantages in arid environments. Methods: We focused on Metrosideros polymorpha, an endemic tree species in the Hawaiian Islands, whose leaves often suffer from galls formed by specialist insects, Hawaiian psyllids (Pariaconus spp.). There is large variation in the amount of leaf trichomes (0–40 % of leaf mass) in M. polymorpha. Three gall types are found on the island of Hawaii: the largest is the ‘cone’ type, followed by ‘flat’ and ‘pit’ types. We conducted laboratory experiments to quantify the extent to which gall formation is associated with leaf water relations. We also conducted a field census of 1779 individuals from 48 populations across the entire range of habitats of M. polymorpha on the island of Hawaii to evaluate associations between gall formation (presence and abundance) and the amount of leaf trichomes. Key Results: Our laboratory experiment showed that leaf minimum conductance was significantly higher in leaves with a greater number of cone- or flat-type galls but not pit-type galls. Our field census suggested that the amount of trichomes was negatively associated with probabilities of the presence of cone- or flat-type galls but not pit-type galls, irrespective of environmental factors. Conclusion: Our results suggest that leaf trichomes in M. polymorpha can contribute to the avoidance of extra water stress through interactions with some gall-making species, and potentially increase the fitness of plants under arid conditions

Relationship between subjective effort and kinematics/kinetics in the 50 m sprint

Purpose. This study investigated the relationship between subjective effort (SE) and kinematics/kinetics throughout an entire 50 m sprint. Methods. Fifteen male sprinters performed the 50 m sprint at 3 different levels of SE (100 %SE; maximal-effort, 90 %SE and 80 %SE, sub-maximal efforts). Kinematic and kinetic data were obtained with a digital high speed camera and 50 ground reaction force (GRF) plates placed every 1 m in the running lane. Variables recorded were sprint time, running speed, step frequency, step length, aerial time, contact time, GRF, and ground reaction impulse (GRI). Results & Discussion. Sprint times decreased with increases in SE. However, some subjects ran their fastest 50m at a sub-maximal SE. Thus, the optimal combination of step length & frequency necessary for obtaining maximum speed does not necessarily occur at maximal SE. Indeed, while step frequency significantly increased with an increase in SE, step length was usually the longest at a sub-maximal SE. The vertical GRI in the first half of the ground contact period was significantly greater at sub-maximal SEs. Vertical GRIs and horizontal GRIs in the second half of the ground contact period did not significantly differ among different SEs. Our results suggest that those runners who increase SF too much at maximal SE do so at the cost of decreasing step length (SL). Thus, applying a large force against the ground in the first half of the ground contact period would be effective for improving step length

Evaluation of platelet reactivity using P2Y12 reaction units in acute coronary syndrome with essential thrombocythemia: A case report

AbstractEssential thrombocythemia (ET) has been reported to cause acute coronary disease. However, the efficacy of anti-platelet therapy for ET is unclear since there are individual differences in the platelet function of ET patients. Here we report a case of a 62-year-old man with ET who was admitted to our hospital because of acute coronary syndrome. He underwent coronary angioplasty. Dual anti-platelet therapy with aspirin (81mg/day) and clopidogrel (75mg/day) was subsequently initiated. We evaluated platelet reactivity in P2Y12 reaction units, and subsequently determined anti-platelet drugs and corresponding doses.<Learning objective: Essential thrombocythemia (ET) is a myeloproliferative disorder that causes acute coronary disease. As there are individual differences in the platelet function of patients with ET, the efficacy of anti-platelet therapy for these patients varies. Evaluation of platelet reactivity using P2Y12 reaction units is useful in determining appropriate anti-platelet drugs and corresponding doses.

Correlation of Optic Nerve Microcirculation with Papillomacular Bundle Structure in Treatment Naive Normal Tension Glaucoma

Purpose. To assess the association between optic nerve head (ONH) microcirculation, central papillomacular bundle (CPB) structure, and visual function in eyes with treatment naive normal tension glaucoma (NTG). Methods. This study included 40 eyes of 40 patients with NTG and 20 eyes of 20 normal patients. We used laser speckle flowgraphy (LSFG) to measure mean blur rate (MBR) in all eyes and calculated the ratio of MBR in the horizontal quadrants of tissue area ONH (temporal/nasal ratio of MBR in the tissue area: T/N MT). Clinical findings also included retinal nerve fiber layer thickness (RNFLT) and ganglion cell complex thickness (GCCT) in the CPB and macular areas, best-corrected visual acuity (BCVA), mean deviation (MD), and refractive error. Results. T/N MT was correlated with both BCVA and MD. The OCT parameters most highly correlated with T/N MT were macular RNFLT and mid-CPB RNFLT. Furthermore, T/N MT, mid-CPB RNFLT, and macular RNFLT were higher in NTG than in normal eyes. A discrimination analysis revealed that T/N MT and refractive error were independent factors indicating NTG. Conclusions. Our results suggest that T/N MT is a candidate biomarker of NTG. Furthermore, T/N MT reflects visual function, including acuity and sensitivity, and CPB structure

Intraspecific differentiation in the root system of Potentilla matsumuraealong a snow accumulation gradient in mid-altitude alpine environment

Despite its importance for plant survival in cold biomes, little is known about the variation in the morphological traits of root systems of alpine plants. In this study, we investigated the difference in biomass allocation and morphological traits of belowground organs ofPotentilla matsumuraebetween snowbeds and fellfields in an alpine tundra in northern Japan. The fellfields were characterized to have drier, colder, and less fertile conditions with more soil freeze-thaw cycles and longer growing seasons than snowbeds. The allocation to the aboveground part relative to the root system was significantly higher in the fellfields than in the snowbeds. The allocation to the root system relative to the aboveground part was significantly lower in the fellfields than in the snowbeds. For the morphological traits of fine roots, the specific root length and the root tip density were smaller in the fellfields than in the snowbeds. Together, distinct intraspecific differentiation of biomass allocation and morphological traits in the root system was found forP. matsumuraebetween the snowbed and fellfields populations in an alpine ecosystem. The distinct variation in root morphology could makeP. matsumuraegrow across the sharp gradient of snow conditions in alpine environments

Estimation Based on Chirp Modulation for Desired and Interference Power and Channel Occupancy Ratio in LoRa

In terms of low power consumption and long-range communication&mdash;low-power wide-area networks (LPWAN) are suitable for wireless sensor networks. Long-range (LoRa) wireless communication is one of the standards of LPWAN. LoRa shares common frequency spectrum bands with both multiple transmitters, which are the sensors in the LoRa system (and those in the other system). Therefore, co-channel interference (CCI) degrades the packet delivery rate. To avoid CCI, the CCI power and the occurrence probability of CCI in the target channel are estimated, then the sensor decides whether to use the channel and where the occurrence probability of CCI is defined as the channel occupancy ratio (COR). If a large signal power is obtained at the receiver, the received signal can be demodulated because of the capture effect. The desired signal power must also be estimated for the capture effect. In this study, we propose an estimation scheme based on chirp modulation of LoRa under spectrum sharing among other systems. The proposed scheme estimates the desired signal power, CCI power, and COR. From the computer simulation results, we clarify the advantages of the proposed scheme in terms of estimation accuracy and packet delivery rate

Relationships between the Slope of the Oxygen Equilibrium Curve and the Cooperativity of Hemoglobin as Analyzed Using a Normalized Oxygen Pressure Scale

Volume: 11Start Page: 663End Page: 66