86 research outputs found

    Charge-selective Permeability of Dermo-epidermal Junction: Tracer Studies with Cationic and Anionic Ferritins

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    To investigate quantitatively the charge-selective permeability of the basement membrane (BM) of the dermo-epidermal junction (DEJ), tracer experiments using anionic and cationic ferritins were performed on an epidermal sheet, whose lamina densa was exposed on the dermal surface; its dermis was removed with forceps after the treatment of newborn rat skin with 10 mM dithiothreitol. The lamina densa and epidermal components of the sheets were electron microscopically well preserved, and anionic sites were ultrastructurally demonstrated on both the dermal and epidermal aspects of the lamina densa in the DEJ as clusters of cationic ferritins (CF) [isoelectric point (pI) > 9.5] or polyethyleneimine particles, indicating that the epidermal sheets were suitable for study of permeability.In tracer experiments, a large number of CF (pI 8.0-9.4) passed the lamina densa and formed clusters on both aspects of the lamina densa and in the intercellular space. The number of native anionic ferritins (NF) (pI 4.1-4.6) passing it was apparently much smaller than that of CF. When the epidermal sheets were pre-treated with protamine sulfate to neutralize the negative charges in the tissue, the number of NF penetrating the lamina densa was significantly larger than the number of those in the untreated sheet.These results indicate that the BM of the DEJ plays a role in a charge-selective filtration, although it is not as selective a barrier as the glomerular basement membrane

    Movements and activities of male black-tailed gulls in breeding and sabbatical years

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    Long-lived animals sometimes skip one or more breeding seasons; however, little is known about their movements and activities during such ‘sabbatical’ periods. Here we present novel data on year-round movements and activities of two male black-tailed gulls Larus crassirostris during a sabbatical year. We compare the data with those in a year when they bred and with those of two other breeding males. The year-round migration routes of two sabbatical males were consistent with those of the breeding males: they returned to the breeding area but did not visit the colony in the sabbatical year. They landed more frequently on water (a potential index of foraging effort) during the non-breeding autumn and winter prior to the sabbatical year than before breeding. Sabbatical gulls may forage more intensively to recover body condition immediately after breeding

    Molecular packing density of a self-assembled monolayer formed from N-(2-aminoethyl)-3-aminopropyltriethoxysilane by a vapor phase process.

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    The molecular density of an aminosilane self-assembled monolayer formed from N-(2-aminoethyl)-3-aminopropyltriethoxysilane (AEAPS) by a vapor phase method has been estimated to be about 3 AEAPS molecules per nm(2) based on chemical labeling, optical absorption spectroscopy and X-ray photoelectron spectroscopy

    Origin of carbon and essential fatty acids in higher trophic level fish in headwater stream food webs

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    Dietary carbon sources in headwater stream food webs are divided into allochthonous and autochthonous organic matters. We hypothesized that: 1) the dietary allochthonous contribution for fish in headwater stream food webs positively relate with canopy cover; and 2) essential fatty acids originate from autochthonous organic matter regardless of canopy covers, because essential fatty acids, such as 20:5ω3 and 22:6ω3, are normally absent in allochthonous organic matters. We investigated predatory fish Salvelinus leucomaenis stomach contents in four headwater stream systems, which are located in subarctic region in northern Japan. In addition, stable carbon and nitrogen isotope ratios, fatty acid profile, and stable carbon isotope ratios of essential fatty acids were analyzed. Bulk stable carbon analysis showed the major contribution of autochthonous sources to assimilated carbon in S. leucomaenis. Surface baits in the stomach had intermediate stable carbon isotope ratios between autochthonous and allochthonous organic matter, indicating aquatic carbon was partly assimilated by surface baits. Stable carbon isotope ratios of essential fatty acids showed a positive relationship between autochthonous sources and S. leucomaenis across four study sites. This study demonstrated that the main supplier of dietary carbon and essential fatty acids was autochthonous organic matter even in headwater stream ecosystems under high canopy cover

    A lightweight data-driven spiking neuronal network model of Drosophila olfactory nervous system with dedicated hardware support

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    Data-driven spiking neuronal network (SNN) models enable in-silico analysis of the nervous system at the cellular and synaptic level. Therefore, they are a key tool for elucidating the information processing principles of the brain. While extensive research has focused on developing data-driven SNN models for mammalian brains, their complexity poses challenges in achieving precision. Network topology often relies on statistical inference, and the functions of specific brain regions and supporting neuronal activities remain unclear. Additionally, these models demand huge computing facilities and their simulation speed is considerably slower than real-time. Here, we propose a lightweight data-driven SNN model that strikes a balance between simplicity and reproducibility. The model is built using a qualitative modeling approach that can reproduce key dynamics of neuronal activity. We target the Drosophila olfactory nervous system, extracting its network topology from connectome data. The model was successfully implemented on a small entry-level field-programmable gate array and simulated the activity of a network in real-time. In addition, the model reproduced olfactory associative learning, the primary function of the olfactory system, and characteristic spiking activities of different neuron types. In sum, this paper propose a method for building data-driven SNN models from biological data. Our approach reproduces the function and neuronal activities of the nervous system and is lightweight, acceleratable with dedicated hardware, making it scalable to large-scale networks. Therefore, our approach is expected to play an important role in elucidating the brain's information processing at the cellular and synaptic level through an analysis-by-construction approach. In addition, it may be applicable to edge artificial intelligence systems in the future

    Self-Expandable Metal Stent Placement as a Bridge to Laparoscopic or Open Surgery for Obstructive Colorectal Cancer: Short-Term Outcomes of Nineteen Consecutive Cases

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    Purpose Laparoscopic colorectal resection is a feasible and less invasive procedure with short-term advantages compared with open surgery; however, the evidence for its efficacy for treating obstructive colorectal cancer (CRC) is lacking. In this study, we aimed to determine short-term outcomes of SEMS placement for obstructive CRC followed by laparoscopic colorectal resection.Methods As of August 2013, 51 patients with obstructive CRC underwent stent insertion. Thirty-two patients received palliation therapy not intended for tumor resection. After decompression of the proximal intestine, nine and 10 patients underwent laparoscopic and open surgery, respectively. Clinicopathological, intraoperative, and postoperative data were retrospectively collected.Results There were no differences in resection rates and curabilities between the two groups. All surgeries were performed with a single-stage anastomosis, and no anastomotic leakage was observed. There was one patient with abdominal morbidity in the open group (Open) and none in the Lap group. There was no mortality in either group. Time to flatus (3.4 ± 1.8 days, Lap; 2.6 ± 1.1 days, Open) and time to oral intake (7.9 ± 2.5 days, Lap; 7.7±1.9 days, Open) were similar between the groups. Postoperative hospitalization times for the Lap group were shorter, but the difference was not statistically significant (15.2 ± 3.9 days, Lap; 21 ± 11.7 days, Open, p = 0.21).Conclusion Our findings indicate that laparoscopic surgery combined with preoperative stent placement is feasible as well as safe compared with open surgery for obstructive CRC

    フェミニズム ト アカデミア ニホン シンリ ガッカイ ダイ 69カイ タイカイ ワークショップ ホウコク

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    The second wave of feminism has challenged a long history of academia where a canon of \u27a man as a normative human,\u27 has implicitly and/or explicitly dominated for centuries. Feminist scholars have questioned validity of traditional theories, research methods, and relationships of researcher/researched, and developed alternative ones in various disciplines. This article includes four scholars\u27 short talks on how feminism has influenced on her/his research field; Drs. Y. Iida, M. Ogawa, T. Kazama and Y. Morinaga from Japanese literature, science studies, gay studies and psychology, respectively. The talks were addressed at a workshop titled \u27feminism and academia\u27 in the 69th annual conference of Japanese Psychological Association, 2005

    Analysis of Chromosome Dynamics during Meiosis I of Arabidopsis thaliana Pollen Mother Cells by Fluorescent In Situ Hybridization(FISH)

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    Since insertion mutagenesis methods, which enabled us to identify the mutagenized genes routinely, were developed for plants, Arabidopsis thaliana has been playing a central role in plant meiosis research. Though several techniques to analyze meiotic chromosome behavior have been introduced into Arabidopsis research since Ross et al. reported the method to observe male meiotic chromosomes of this plant through light microscope in 1996 (Chromosome Res. 4-507-516), intimate analysis of the chromosome behavior has not been accomplished. Taking advantage of the recent development of new nucleotides labeled with fluorescent dyes, we investigated chromosome behavior during male meiosis by multicolor FISH. Telomeres found around nucleoli in premeiotic interphase cells dispersed after entering meiosis, then clustered in a bouquet-like configuration. Statistically, telomeres of homologous chromosomes paired earlier than centromeres, but when respective chromosomes were examined, the telomeres were not always quick to pair. At early prophase I, possibly at around the zygotene stage, the signals from telomeres reduced to less than ten. This reduction suggests that the paired telomeres of homologous chromosomes temporally associate with other telomeres to look for their real partners. When homologous chromosomes separated at anaphase I, telomeres were always last to segregate. This suggested that there was unknown interaction between the telomeres of homologs, connecting them until anaphase I started
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