Unusual CT and MR Imaging Characteristics of Splenic Lymphoma

Lymphoma is the most common malignancy of the spleen. The imaging features of splenic lymphoma are nonspecific and mostly lymphomas present as a diffusely enlarged spleen. Focal lesions are described but remain of low density or intensity on CT or MRI, respectively. We describe a histologically proven case of splenic lymphoma that showed an atypical hyperdense/hyperenhancing appearance on imaging suspicious for a vascular pathology. To the best of our knowledge and based on review of English literature, such an appearance of splenic lymphoma is extremely unusual and rare

Numerical modeling and analysis of evaporative salinization in a coupled free-flow porous-media system

Interaction between fluid in the porous medium and the conjugate free flow is observed in many natural and technical applications. In these applications, the flow and transport processes in the porous medium and in the free flow display strong interdependency. This is also influenced by the mechanisms of interaction at the common interface between the porous medium and the free flow. Studying these mechanisms plays a significant role in understanding the interaction behavior of these systems. Moreover, it is also important for the numerical modeling of such systems. An environmental example of such a system is evaporative drying of the shallow sub-surface subjected to the atmospheric free flow. As it significantly influences the terrestrial water balance and soil salinization, developing a detailed understanding about such a coupled system is very important. Furthermore, salt precipitation associated with evaporation from the shallow sub-surface directly affects the fertility of the soil. This becomes significantly important in the arid, semi-arid or coastal regions, where water from the deep hydrological systems is largely used for irrigation. Literature review shows that the soil salinization associated with the promoted irrigation is a major problem for farmers worldwide, as it directly influences the crop yield. In such systems, the evaporative salinization is influenced by the ambient air velocity, temperature and humidity on the free flow side and, by the soil properties and properties of water used for irrigation on the porous-media side. Therefore, for studying the evaporation and salinization dynamics in such systems, developing a detailed understanding of the underlying processes is very important and, elaborations using the modeling tools are very crucial. The main focus of this PhD thesis is to study evaporative salinization in the shallow sub-surface exposed to the adjacent atmospheric free flow. For this purpose, in the first part of this work, we develop a coupled model concept which describes a two-phase compositional porous-media system coupled with a single-phase compositional free flow. The developed REV scale model is robust and capable of comprehensive analysis of the exchange processes for mass, momentum and energy between the free flow and the porous medium. The developed model concept is implemented in the numerical framework of the open source porous-media simulator DuMux. In a natural hydrogeochemical system mixed salt precipitates is frequently observed. Therefore, in the second part, the model is extended to describe reactive transport of dissolved ionic species. Here, chemistry driven approaches are used to describe the salt precipitation processes. In addition to this, the model also accounts for solid salt accumulation driven changes in the porous media properties. Moreover, it provides the flexibility to analyze the influence of different free flow and porous media processes and parameters on evaporation and salinization dynamics. Evaporative salinization experiments was performed by the research group of Professor Nima Shokri at the University of Manchester. During these experiments saline-water saturated sand-columns were exposed to drying in an environmental chamber. The data from these experiments is used for model validation in this work. The first validation study is carried out using the simplified model for stage SS1 of evaporative salinization. Here, dissolved salt (NaCl) is assumed to be a single component and equilibrium based approach is used for salt precipitation. Thus, during evaporation, spontaneous salt precipitation is expected as dissolved salt in the solution reaches its solubility limit. For this approach, the validation study has shown excellent agreement between the model results and experimental observations. This simplified model is then applied for all stages of saline water evaporation. The comparison between numerical and experimental results was promising. However, the numerical results has shown divergence from the experimental observations in late stage SS1 and during transition to stage SS2. To understand these differences, a details parameter analysis is carried out. For this, influence of the free flow, porous medium and their interface on evaporation and salinization dynamics is analyzed. The parameter analysis highlighted that the variation in individual parameters or processes in the free flow, porous medium or at their interface can significantly influence evaporation and salt precipitation behavior. In the second validation study, the extended model is applied to analyze precipitation dynamics in a mixed salt (NaCl-NaI) system. Here, in order to account for salt precipitation process both equilibrium and kinetic reaction based approaches are developed. These approaches are first validated using the available experimental data for single salt (NaCl) precipitation. This validation indicated that both the equilibrium and kinetic precipitation approaches are well in accordance with the experimental observations. Furthermore, for mixed salt precipitation (NaCl-NaI), the simulation results are found to be in good accordance with the phenomenological explanations discussed in the literature. Due to lack of experimental data, the mixed salt precipitation model will be validated in the near future. We conclude that the developed model concept offers a comprehensive and robust framework for modeling dissolved salt transport and precipitation processes in the drying shallow subsurface interacting with the free flow. Moreover, the validation studies indicate that the model is reliable to study and analyze the reactive transport and mixed salt precipitation processes in a naturally occurring hydrogeochemical system. Furthermore, generic nature of the developed model allows direct extension to other salinization applications where salt precipitation is observed at the interface between free flow and porous medium

RNA Stimulates Aurora B Kinase Activity during Mitosis

Accurate chromosome segregation is essential for cell viability. The mitotic spindle is crucial for chromosome segregation, but much remains unknown about factors that regulate spindle assembly. Recent work implicates RNA in promoting proper spindle assembly independently of mRNA translation; however, the mechanism by which RNA performs this function is currently unknown. Here, we show that RNA regulates both the localization and catalytic activity of the mitotic kinase, Aurora-B (AurB), which is present in a ribonucleoprotein (RNP) complex with many mRNAs. Interestingly, AurB kinase activity is reduced in Xenopus egg extracts treated with RNase, and its activity is stimulated in vitro by RNA binding. Spindle assembly defects following RNase-treatment are partially rescued by inhibiting MCAK, a microtubule depolymerase that is inactivated by AurB-dependent phosphorylation. These findings implicate AurB as an important RNA-dependent spindle assembly factor, and demonstrate a translation-independent role for RNA in stimulating AurB

Relationship between lake area and distance from the city centre on lake-dependent resident and migratory birds in urban Bangalore, a tropical mega-city in Southern India

Urbanization is one of the major causes of biodiversity loss worldwide. Some species are able to adapt to urbanization, whereas others perish. Studies on long-term effects of the impact of urbanization on species diversity and abundance patterns are especially lacking from tropical cities. We seek to assess the relationship between urbanization and species richness of lake-dependent birds in Bangalore, a tropical mega-city in Southern India. We specifically ask: (i) How is bird species richness related to the size of the lake? (ii) How is bird species richness in Bangalore’s lakes related to the degree of urbanization? We used data from 2014 to 2019, collected from eBird—an online database that collates information on bird observations globally. Both lake area and distance from the city centre are correlated to species richness, with larger lakes supporting more bird species. As distance from the city centre increased (i.e. urbanization decreases), bird richness increased. Overall, in the city of Bangalore, migratory birds have declined while many lake-dependent resident birds seem to be increasing over the past 5 years. We hypothesize that birds that roost and nest in trees appear to be increasing. To confirm this, further research taking a trait-based approach is required. Urbanization appears to have species-specific impacts on lake-dependent birds in this tropical city, with certain groups of birds faring better than others. This research adds to the significant paucity of studies of the impact of urbanization on biodiversity in the urban tropics

The influence of the preparation methods on the inclusion of model drugs in a β-cyclodextrin cavity

NOTICE: this is the author’s version of a work that was accepted for publication in European Journal of Pharmaceutics and Biopharmaceutics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Eur J Pharm Biopharm. 2009 Feb;71(2):377-386. Epub 2008 Oct 17.The work aims to prove the complexation of two model drugs (ibuprofen, IB and indomethacin, IN) by bcyclodextrin (bCD), and the effect of water in such a process, and makes a comparison of their complexation yields. Two methods were considered: kneading of a binary mixture of the drug, bCD, and inclusion of either IB or IN in aqueous solutions of bCD. In the latter method water was removed by air stream, spray-drying and freeze-drying. To prove the formation of complexes in final products, optical microscopy, UV spectroscopy, IR spectroscopy, DSC, X-ray and NMR were considered. Each powder was added to an acidic solution (pH = 2) to quantify the concentration of the drug inside bCD cavity. Other media (pH = 5 and 7) were used to prove the existence of drug not complexed in each powder, as the drugs solubility increases with the pH. It was observed that complexation occurred in all powders, and that the fraction of drug inside the bCD did not depend neither on the method of complexation nor on the processes of drying considered

Which traits influence bird survival in the city? a review

Urbanization poses a major threat to biodiversity worldwide. We focused on birds as a well-studied taxon of interest, in order to review literature on traits that influence responses to urbanization. We review 226 papers that were published between 1979 and 2020, and aggregate information on five major groups of traits that have been widely studied: ecological traits, life history, physiology, behavior and genetic traits. Some robust findings on trait changes in individual species as well as bird communities emerge. A lack of specific food and shelter resources has led to the urban bird community being dominated by generalist species, while specialist species show decline. Urbanized birds differ in the behavioral traits, showing an increase in song frequency and amplitude, and bolder behavior, as compared to rural populations of the same species. Differential food resources and predatory pressure results in changes in life history traits, including prolonged breeding duration, and increases in clutch and brood size to compensate for lower survival. Other species-specific changes include changes in hormonal state, body state, and genetic differences from rural populations. We identify gaps in research, with a paucity of studies in tropical cities and a need for greater examination of traits that influence persistence and success in native vs. introduced populations

Kaposiform hemangioendothelioma in tonsil of a child associated with cervical lymphangioma: a rare case report

Kaposiform hemangioendothelioma (KHE) is an uncommon vascular tumor of intermediate malignant potential, usually occurs in the extremities and retroperitoneum of infants and is characterized by its association with lymphangiomatosis and Kasabach-Merritt phenomenenon (KMP) in certain cases. It has rarely been observed in the head and neck region and at times, can present without KMP. Herein, we present an extremely uncommon case of KHE occurring in tonsil of a child, associated with a neck swelling, but unassociated with KMP. A 2-year-old male child referred to us with history of sore throat, dyspnoea and right-sided neck swelling off and on, since birth, was clinicoradiologically diagnosed with recurrent tonsillitis, including right sided peritonsillar abscess, for which he underwent right-sided tonsillectomy, elsewhere. Histopathological sections from the excised tonsillar mass were reviewed and showed a tumor composed of irregular, infiltrating lobules of spindle cells arranged in kaposiform architecture with slit-like, crescentic vessels. The cells displayed focal lumen formation containing red blood cells (RBCs), along with platelet thrombi and eosinophilic hyaline bodies. In addition, there were discrete foci of several dilated lymphatic vessels containing lymph and lymphocytes. On immunohistochemistry (IHC), spindle cells were diffusely positive for CD34, focally for CD31 and smooth muscle actin (SMA), the latter marker was mostly expressed around the blood vessels. Immunostaining for HHV8 was negative and Ki-67 (proliferation marker) displayed focal positivity. Diagnosis of KHE was made. Platelet count was towards lower side of range. Postoperative imaging showed discrete, multiple fluid containing lesions in the right neck that were high on T2-weighed sequences, on magnetic resonance imaging (MRI) and ipsilateral intraoral mucosal growth. Fine needle aspiration cytology (FNAC) smears from neck swelling showed blood, fluid and lymphocytes. Possibility of a coexisting lymphangioma was considered. The patient was offered sclerotherapy and is on follow-up. This case forms the second documented case of KHE at this site, along with its unique association with neck lymphangioma. KHE has distinct histopathological features and can be sorted out from its other differentials like juvenile hemangioma and Kaposi's sarcoma. IHC stains are useful in substantiating a definite diagnosis