236 research outputs found

    Sex-specific retinal pigmentation results in sexually dimorphic long-wavelength-sensitive photoreceptors in the Eastern Pale Clouded Yellow butterfly,Colias erate.

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    The compound eyes of the eastern pale clouded yellow butterfly, Colias erate, contain three types of ommatidia (I, II and III), identifiable by the differing arrangements of pigment clusters around the rhabdoms. The pigment color is red in all ommatidial types except for type II ommatidia of females, where the pigment is orange. Intracellular recordings demonstrated that the spectral sensitivities of the proximal photoreceptors (R5–8) of all ommatidia in both sexes are strongly tuned by the perirhabdomal pigments. These pigments act as long-pass filters, shifting the peak sensitivities into the wavelength range above 600 nm. Due to the sex-specific pigments in type II ommatidia, the spectral sensitivities of the R5–8 photoreceptors of females peaked at 620 nm while those in males peaked at 660 nm. The measured spectral sensitivities could be well reproduced by an optical model assuming a long-wavelength-absorbing visual pigment with peak absorbance at 565 nm. Whereas the sexual dimorphism was unequivocally demonstrated for the ventral eye region, dimorphism in the dorsal region was not found. Presumably the ventral region is adapted for sexual behaviors such as courtship and oviposition

    How Did the Dollar Peg Fail in Asia?

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    In this paper we have constructed a theoretical model in which Asian firms maximize their profit, competing with Japanese and US firms in their markets. The duopoly model is used to determine export prices and volumes in response to the exchange rate fluctuations vis-…-vis the Japanese yen and the US dollar. Then, the optimal basket weight to minimize the fluctuation of the growth rate of trade balance is derived. These are the novel features of our model. The export price equation and export volume equation are estimated for several Asian countries for the sample period of 1981 to 1996. Results are generally reasonable. The optimal currency weights for the yen and the US dollars are derived and compared with actual weights that had been adopted before the currency crisis of 1997. For all the countries in the sample, it is shown that the optimal weight of the yen is significantly higher than the actual weight.

    Regional differences in the preferred e-vector orientation of honeybee ocellar photoreceptors

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    In addition to compound eyes, honeybees (Apis mellifera) possess three single lens eyes called ocelli located on the top of the head. Ocelli are involved in head-attitude control and in some insects have been shown to provide celestial compass information. Anatomical and early electrophysiological studies have suggested that UV and blue-green photoreceptors in ocelli are polarization sensitive. However, their retinal distribution and receptor characteristics have not been documented. Here, we used intracellular electrophysiology to determine the relationship between the spectral and polarization sensitivity of photoreceptors and their position within the visual field of the ocelli. We first determined a photoreceptor’s spectral response through a series of monochromatic flashes (340 - 600 nm). We found UV and Green receptors, with peak sensitivities at 360 nm and 500 nm respectively. We subsequently measured polarization sensitivity at the photoreceptor’s peak sensitivity wavelength by rotating a polarizer with monochromatic flashes. Polarization sensitivity (PS) values were significantly higher in UV receptors (3.8±1.5, N=61) than Green receptors (2.1±0.6, N=60). Interestingly, most receptors with receptive fields below 35° elevation were sensitive to vertically polarized light while the receptors with visual fields above 35° were sensitive to a wide range of polarization angles. These results agree well with anatomical measurements showing differences in rhabdom orientations between dorsal and ventral retinae. We discuss the functional significance of the distribution of polarization sensitivities across the visual field of ocelli by highlighting the information the ocelli are able to extract from the bee’s visual environment.This study was supported by a Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellowship for Research Abroad to Y.O. and an Australian Research Council grant (FT110100528) to J.M.H

    Seminal fluid compromises visual perception in honeybee queens reducing their survival during additional mating flights

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    Queens of social insects make all mate-choice decisions on a single day, except in honeybees whose queens can conduct mating flights for several days even when already inseminated by a number of drones. Honeybees therefore appear to have a unique, evolutionarily derived form of sexual conflict: a queen's decision to pursue risky additional mating flights is driven by later-life fitness gains from genetically more diverse worker-offspring but reduces paternity shares of the drones she already mated with. We used artificial insemination, RNA-sequencing and electroretinography to show that seminal fluid induces a decline in queen vision by perturbing the phototransduction pathway within 24-48 hr. Follow up field trials revealed that queens receiving seminal fluid flew two days earlier than sister queens inseminated with saline, and failed more often to return. These findings are consistent with seminal fluid components manipulating queen eyesight to reduce queen promiscuity across mating flights

    アミロース-アミロペクチン混合溶液の非ニュートン粘性挙動

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    東京水産大学食品生産化学講座東京水産大学食品生産化学講座東京水産大学食品生産化学講座東京水産大学食品生産化学講座東京水産大学食品生産化学講

    Percutaneous coronary intervention strategy for acute coronary syndrome caused by spontaneous coronary artery dissection for relieving ongoing ischemia—Case series and literature review

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    AbstractAlthough spontaneous coronary artery dissection (SCAD) is one of the causes of acute coronary syndrome (ACS) or sudden cardiac death, its standard management, especially primary percutaneous coronary intervention (PCI) in ACS patients with ongoing ischemia, has not been established. We experienced three ACS patients with SCAD who were treated with a different strategy of primary PCI. Each PCI strategy led to different clinical and procedural results. We describe here such PCI strategies and results, and also discuss the literature regarding primary PCI strategies for SCAD-induced ACS patients with ongoing ischemia.<Learning objective: SCAD is a cause of ACS. However, the treatment strategy of primary PCI for SCAD has not been fully investigated. We used different PCI strategies for three SCAD patients with ongoing ischemia. Our case series suggested that plain old balloon angioplasty is an acceptable option to avoid coronary stenting because the majority of patients were young menstruating women. Coronary vasospasm might be associated with SCAD. Treatment with vasodilators could be a potential pharmacological option for avoiding recurrence of SCAD.

    Fusion partner–specific mutation profiles and KRAS mutations as adverse prognostic factors in MLL-rearranged AML

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    急性骨髄性白血病の予後を予測する新規マーカーを発見 --リスクに応じた適切な治療につながる可能性--. 京都大学プレスリリース. 2020-10-02.Mixed-lineage leukemia (MLL) gene rearrangements are among the most frequent chromosomal abnormalities in acute myeloid leukemia (AML). MLL fusion patterns are associated with the patient’s prognosis; however, their relationship with driver mutations is unclear. We conducted sequence analyses of 338 genes in pediatric patients with MLL-rearranged (MLL-r) AML (n = 56; JPLSG AML-05 study) alongside data from the TARGET study’s pediatric cohorts with MLL-r AML (n = 104), non–MLL-r AML (n = 581), and adult MLL-r AML (n = 81). KRAS mutations were most frequent in pediatric patients with high-risk MLL fusions (MLL-MLLLT10, MLL-MLLT4, and MLL-MLLT1). Pediatric patients with MLL-r AML (n = 160) and a KRAS mutation (KRAS-MT) had a significantly worse prognosis than those without a KRAS mutation (KRAS-WT) (5-year event-free survival [EFS]: 51.8% vs 18.3%, P < .0001; 5-year overall survival [OS]: 67.3% vs 44.3%, P = .003). The adverse prognostic impact of KRAS mutations was confirmed in adult MLL-r AML. KRAS mutations were associated with adverse prognoses in pediatric patients with both high-risk (MLLT10+MLLT4+MLLT1; n = 60) and intermediate-to-low–risk (MLLT3+ELL+others; n = 100) MLL fusions. The prognosis did not differ significantly between patients with non–MLL-r AML with KRAS-WT or KRAS-MT. Multivariate analysis showed the presence of a KRAS mutation to be an independent prognostic factor for EFS (hazard ratio [HR], 2.21; 95% confidence interval [CI], 1.35-3.59; P = .002) and OS (HR, 1.85; 95% CI, 1.01-3.31; P = .045) in MLL-r AML. The mutation is a distinct adverse prognostic factor in MLL-r AML, regardless of risk subgroup, and is potentially useful for accurate treatment stratification. This trial was registered at the UMIN (University Hospital Medical Information Network) Clinical Trials Registry (UMIN-CTR; http://www.umin.ac.jp/ctr/index.htm) as #UMIN000000511
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