Comparative analysis of vertebrates reveals that mouse primordial oocytes do not contain a Balbiani body

Oocytes spend the majority of their lifetime in a primordial state. The cellular and molecular biology of primordial oocytes is largely unexplored; yet, studying these is necessary to understand the mechanisms through which oocytes maintain cellular fitness for decades, and why they eventually fail with age. Here, we develop enabling methods for live-imaging based comparative characterization of Xenopus, mouse and human primordial oocytes. We show that primordial oocytes in all three vertebrate species contain active mitochondria, Golgi apparatus and lysosomes. We further demonstrate that human and Xenopus oocytes have a Balbiani body characterized by a dense accumulation of mitochondria in their cytoplasm. However, despite previous reports, we did not find a Balbiani body in mouse oocytes. Instead, we demonstrate what was previously used as a marker for the Balbiani body in mouse primordial oocytes is in fact a ring-shaped Golgi apparatus that is not functionally associated with oocyte dormancy. Our work provides the first insights into the organisation of the cytoplasm in mammalian primordial oocytes, and clarifies relative advantages and limitations of choosing different model organisms for studying oocyte dormancy.

On the Cluster Formation of α-Synuclein Fibrils

The dense accumulation of α-Synuclein fibrils in neurons is considered to be strongly associated with Parkinson’s disease. These intracellular inclusions, called Lewy bodies, also contain significant amounts of lipids. To better understand such accumulations, it should be important to study α-Synuclein fibril formation under conditions where the fibrils lump together, mimicking what is observed in Lewy bodies. In the present study, we have therefore investigated the overall structural arrangements of α-synuclein fibrils, formed under mildly acidic conditions, pH = 5.5, in pure buffer or in the presence of various model membrane systems, by means of small-angle neutron scattering (SANS). At this pH, α-synuclein fibrils are colloidally unstable and aggregate further into dense clusters. SANS intensities show a power law dependence on the scattering vector, q, indicating that the clusters can be described as mass fractal aggregates. The experimentally observed fractal dimension was d = 2.6 ± 0.3. We further show that this fractal dimension can be reproduced using a simple model of rigid-rod clusters. The effect of dominatingly attractive fibril-fibril interactions is discussed within the context of fibril clustering in Lewy body formation.

Nature of a white opaque substance visualized by magnifying endoscopy in colorectal hyperplastic polyps

Background and study aims A white opaque substance (WOS) has been observed in the epithelia of gastric, duodenal, and colorectal epithelial adenomas and carcinomas, using magnifying endoscopy (ME). The WOS has been reported to be derived from a dense accumulation of minute lipid droplets in the epithelium. This study aimed to investigate whether the WOS in colorectal hyperplastic polyps was derived from lipid droplets accumulated in the epithelium, as observed in the case of gastric, duodenal, and colorectal epithelial neoplasms. Patients and methods We analyzed 30 consecutive patients who were positive for the WOS, as visualized in colorectal hyperplastic polyps by ME with narrow-band imaging and 30 consecutive patients who were negative for the WOS. Biopsy specimens obtained from the polyps were immunostained with anti-adipophilin antibody to determine the correlation between the presence of the WOS and that of lipid droplets in the epithelium. Results In all patients, the epithelial cells were histologically positive for adipophilin. However, the area of adipophilin-positive epithelial cells in the WOS-positive group was significantly larger than that in the WOS-negative group (P < 0.001). The density of the WOS was strongly and positively correlated with the area of adipophilin-positive cells. Conclusions This study reveals that the WOS visualized in the superficial layers of colorectal hyperplastic polyps is produced by a dense accumulation of minute lipid droplets in the epithelia of the polyps.

Histopathology of the Foot, Gill and Digestive Gland Tissues of Freshwater Mussel, Lamellidens marginalis Exposed to Oil Effluent

We investigated the histopathological alterations in the tissues of freshwater mussel, Lamellidens marginalis in response to oil effluent. Based on the previous acute toxicity, two sub lethal [1/4th (11.88ppt) and 1/10th (8.55ppt)] concentrations of oil effluent (hydrocarbon) were prepared and exposed to mussels. In a first series of experiment, animals were exposed/accumulated for 30 days [Ist, 8th, 15th, 22nd and 30th days] by two sub lethal concentrations of oil. In a second series of experiment, oil exposed animals were thereafter transferred to clean water and kept in it up to 30 days [Ist, 8th, 15th, 22nd and 30th days] to assess the recovery pattern (depuration). At seven-day intervals, histopathological alterations were analyzed in foot, gill and digestive gland tissues of mussel. First series of experimental observation showed remarkable damages in foot (disorganized outer epithelium, necrosis of the cell, the formation of lumina, disorganized muscle bundle); in gill (disruption of gill filaments, odema formation, necrosis, dis-aggregated cilia) and in digestive gland (stoma, detached glandular epithelium, vertical clefts, presence of leucocytes, dense accumulation of luminal material) and also oil effluent inducement are confirmed with the aforementioned results. At second series of experiment, it was found that oil effluent tended to accumulate in tissues in a duration-dose-dependent manner. Tissue burden by oil effluent of mussels completely were restored at 30th day. The present experimental findings may be of early warning signals of oil effluent pollution. In conclusion oil effluent are highly toxic to the Lamellidens marginalis.

Fear, Humanity and Managing the Heritage of War

Using the concepts of affective community (Ahmed 2015; Hutchison 2016) and affective management of “war heritage” (Logan and Reeves 2009; Gegner and Ziino 2012; Lončar 2014; Stublić 2019), the article examines how social subjects in Western Slavonia – a microlocation with many places of memory and a dense accumulation of historical traumas within them – are constructed as resisting and/or conforming to the dominant hegemonic policy of remembering the Homeland War as the “cornerstone of reasoning” in Croatia (Blanuša 2017). The examples analysed range from the activities of a local “memory agent” and the founder of a digital archive of local history to the reception of a book of testimonies and a documentary on the humanity of Pakrac’s medics in the war (Lessons on Humanity, 2017 and 2019). Based on these examples, I identified different strategies of cultural, pedagogical and ideological re-presentation and re-animation of local war heritage in the social and digital environment. These strategies are different responses to the fear that the feeling of social connection to war events and veterans as symbols of national unity and pride has been ebbing away. However, there has also been a noticeable shift on the Croatian (semi-)periphery from a ceremonial commemorative culture to a digital culture of memory of war, fostered by affective communities which transcend local, ethnic and generational boundaries. The second shift is semantic – the tendency to replace victimological and triumphalist war narratives with those of “humanitarian heroism” and positive war stories about humanity, about helping and rescuing people from the “enemy side”. In conclusion, even though the Croatian “social framework of memory” (Halbwachs 2013) offers different models for transforming fear, pain, violence and the trauma of war into “cultural heritage”, only individuals remember and feel, and very few among them become memory agents and activists of “mnemonic resistance” (Molden 2016) with a significant role in the struggles over the meaning of the past.

KAKU4-mediated deformation of the vegetative nucleus controls its precedent migration over sperm cells in pollen tubes

A putative nuclear lamina protein, KAKU4, modulates nuclear morphology in Arabidopsis thaliana seedlings but its physiological significance is unknown. KAKU4 was strongly expressed in mature pollen grains, each of which has a vegetative cell and two sperm cells. KAKU4 protein was highly abundant on the envelopes of vegetative nuclei (VNs) and less abundant on the envelopes of sperm cell nuclei (SCNs) in pollen grains and elongating pollen tubes. VN is irregularly shaped in wild-type pollen. However, KAKU4 deficiency caused it to become more spherical. These results suggest that the dense accumulation of KAKU4 is responsible for the irregular shape of the VNs. After a pollen grain germinates, the VN and SCNs migrate to the tip of the pollen tube. In the wild type, the VN preceded the SCNs in 91–93% of the pollen tubes, whereas in kaku4 mutants, the VN trailed the SCNs in 39–58% of the pollen tubes. kaku4 pollen was less competitive than wild-type pollen after pollination, although it had an ability to fertilize. Taken together, our results suggest that controlling the nuclear shape in vegetative cells of pollen grains by KAKU4 ensures the orderly migration of the VN and sperm cells in pollen tubes.HighlightThe nuclear envelope protein KAKU4 is involved in controlling the migration order of vegetative nuclei and sperm cells in pollen tubes, affecting the competitive ability of pollen for fertilization.

ANATOMICAL STUDIES OF THE FRUIT OF ZIZIPHUS RUGOSA

Objective: The objective of this study was to study the anatomical features of the fruit Ziziphus rugosa. Methods: Surface view, longitudinal, transverse section (T.S), and powder microscopy of the fruits were studied. Results: The fruit is a drupe and shows vertical, irregular brown markings on the surface. The surface of the seed has irregular reticulate thick marking of brown. The longitudinal sections (L.S) of the fruit show thin green epicarp, wide soft mesocarp, and dark brown thick endocarp. In longitudinal view, the seed shows a thick conical part, thick wide shell which is hard. In the cotyledon is more or less cordate,white and soft with shallow notch at the upper end. In T.S, the fruit appears circular with soft pericarp, thick dark brown seed coat of sclereids, and vertically elongated white cotyledon. The epicarp layer is broken at certain places. In the mesocarp, some of the cells have dense tannin content and others have mucilage substance. The mucilaginous canals are wide, unbranched, and wavy. Some of the mesocarp cells contain dense accumulation of protein bodies. The sclerotesta contains palisade or macrosclereids. The seed consists of two elliptical, flat cotyledons which show dense accumulation of starch grains and small less prominent vascular strand. The powder microscopy of the fruit contains abundant dark mucilaginous substance. Fragments of epidermal cells of the pericarp and mesocarp cells are frequently seen. The seed coat epidermal cells are polyhedral with lignified cell walls. The circular brachy sclereids were often seen in the mesophyll tissue of the fruit. The ground parenchyma with various shapes and size is also noticed. Conclusion: This study revealed the presence of mucilaginous substance, tannin, sclereids, starch grains, and protein bodies. Therefore, this material will be efficient for eliminating some nutritional deficiency diseases.

Cage fusion from bi-cages to tri-cages during nucleation of methane hydrate: a DFT-D simulation

Water-cages tend to form dense accumulation configurations; and 512 and 4151062 cages are abundant in the early nucleation stage of CH4 hydrates.

Separation Anxiety: Canine Narrators and Modernist Isolation in Woolf, Twain, and Panizza

In the decades around 1900, the Western literary canon boasts a dense accumulation of stories that specifically make dogs their protagonists, or even their narrators. Authors amongst the most important voices of modernism in their respective traditions, such as Virginia Woolf, Mark Twain, Franz Kafka, O. Henry, Miguel de Unamuno, Vladimir Bulgakov, and Italo Svevo, all turned to canine perspectives to discuss the human condition in the rapidly changing modern world.1 Modernism entailed, among other characteristics, fundamental skepticism of the human self-conception, including the epistemological insecurity of how one might fully know oneself or others and doubt about the ability of language to communicate meaning.2 I argue that the turn to animals in the literary production of this time parses out three interconnected anxieties of modernism: 1) the growing isolation of the individual subject (which a companion animal can and cannot solve); 2) the Sprachkrise, a crisis of language and meaning (in which the limitations of language are addressed via depictions of canine thoughts or words); and 3) concerns about physiognomy and race theory (encoded by dog breeds), which lead to the violent subdual of Others – be they animal, female, or non-white – thus prompting questions about the “humanity” of humankind. The turn to dogs as one of, if not, the animal species sharing human everyday life in the literary engagement with these questions both illustrates and suggests ways of overcoming this isolation and its violence. On the following pages, I first briefly outline the three anxieties regarding isolation, language, and breedist violence in modernism and then draw on three canine narratives, Virginia Woolf’s Flush: A Biography (1933), Mark Twain’s A Dog’s Tale (1903), and Oskar Panizza’s Aus dem Tagebuch eines Hundes (From the Diary of a Dog, 1892), in order to unfold these three entangled points. <?page nr="154"?>The texts are selected as representative both because they bring out these modernist anxieties very clearly, while nonetheless approaching the representation of dogs in three different ways, and because they span a wide historical and national range through their British, American, and German origins across four decades, while still being distinctly anchored in the Euro-Western constellation that gave rise to these modernist anxieties. Each texts places a slightly different emphasis on the three aspects of the argument, and therefore my reading of them is divided into two parts: the first explicates the interplay of modernist isolation and the language crisis with the help of Woolf’s and Panizza’s works, while the second turns to the issue of breed with Woolf and Twain, whose texts highlights the violent consequences and ethical implications of these ideas.

Experimental Studies on the Influence of Gradation of Recycled Coarse Aggregates to the Strength of Self-Compacting Concrete

To make full use of waste clay bricks, we made recycled coarse aggregate by waste clay bricks and used it in self-compacting recycled concrete. In order to improve the utilization rate of recycled coarse aggregate and realize good workability, we adopted skeleton dense accumulation method. With the fitted curve method, we obtained an accumulation curve of recycled coarse aggregate with reasonable gradation. Under the same conditions, we made contrast test with the recycled coarse aggregate by different gradation way. Through contrast test, we found that the recycled concrete with skeleton dense accumulation method has better performance in strength and workability, and his method improved the utilization rate of the recycled coarse aggregate.