A STUDY ON SUDDEN EXPANSION HYDRODYNAMIC PHENOMENA OCCURRING IN CYLINDRICAL PIPES

Introduction: This paper studies the frequency with which hydrodynamic parameters change in the sudden expansion section of axisymmetric pressure flow, based on the boundary layer equations. Methods: The suggested method reveals the regularity of changes in the hydrodynamic parameters of the flow in the transitional area, making it possible to obtain a velocity profile in any cross-section under common initial and boundary conditions. Based on the general solutions, we studied the hydrodynamic processes occurring in the transitional area of the effective sudden cross-section expansion within the axisymmetric pressure movement, in the following cases: a) when the velocity is constant at any point of the inlet face; b) when the velocity is distributed along the inlet face according to the parabolic law. Our calculations were carried out for different values of the expansion factor. Results: Based on the results of the computer-aided experimental study, we obtained velocity diagrams along the length of the transitional area with constant and parabolic velocity distributions for fluid inflowing into the expanded section. We also determined the patterns of pressure distribution along the length of the relevant section.

The Big Naked-backed Bat, Pteronotus gymnonotus, Chiroptera, Mormoopidae, in its northernmost geographic distribution range

The Big Naked-backed Bat, Pteronotus gymnonotus, is one of the 15 species currently recognized of this genus, with relatively few specimens in scientific collections, besides being poorly studied. It has a geographical distribution spanning from México through Central America and reaching Perú and Brazil, in which it occupies a variety of habitats from desert to tropical forests below 400 meters above sea level. Here, we report the records that demonstrate its presence, and data about its natural history in southeastern México, the northernmost part of its geographic distribution range. Between June 2002 and July 2018, we captured specimens in 44 bat roosts located in southeastern México, including the Parque Estatal Agua Blanca, Macuspana, Tabasco; Grutas de Martínez de la Torre, Matías Romero Avendaño, Oaxaca; and in Cueva de Villa Luz, Tapijulapa, Tabasco. In the three locations mentioned, we recorded the occurrence of P. gymnonotus individuals, whose taxonomic identification at species level was corroborated by both morphological data and genetic analyses. Previously, the only records of P. gymnonotus in México were from only four specimens scattered across time, so these new recorded locations confirm the presence of this species in the country. In addition to this, in Agua Blanca State Park and Villa Luz Cave we found a reproductive resident population. The record from Grutas de Martínez de la Torre is located in the middle of the Tehuantepec Isthmus, a well known biogeographical barrier for many taxa in the transitional area to the Pacific lowland’s region. We suggest that the occurrence of P. gymnonotus in México is also associated with large remnants of evergreen and gallery forests, located in the lowland areas along the Gulf of México and in the north and east of the Tehuantepec Isthmus.

Resource partitioning between Microlophus occipitalis and Stenocercus puyango (Sauria: Tropiduridae) in Cerros de Amotape National Park, Tumbes, Peru

Activity, microhabitat use, and diet are patterns commonly used to define the saurian community structure, because of differential exploitation allowing coexistence at the same time and place. We analyze resource partitioning between two sympatric saurian species, Stenocercus puyango and Microlophus occipitalis, in the transitional area of the Pacific Tropical Forest and the Dry Forest inside Cerros de Amotape National Park (PNCA) in Tumbes, northwestern of Peru. Microlophus occipitalis and S. puyango both showed a unimodal activity pattern with higher activity around 13:00 h, with a mean body temperature of 34.83 °C and 32.17 °C respectively, observing a significant relationship between body and environmental (air and substrate) temperatures. Rocks and tree trunks were the most frequent microhabitats used by M. occipitalis while S. puyango were registered more frequently over leaf litter. The diets of both tropidurids were composed by arthropods, ants, and insect larvae mainly. Similarities in activity times (temporal niche) and diet (trophic niche) should be related to phylogenetic relationship and environmental characteristics of PNCA (seasonality, vegetal composition) meanwhile differences in space use and microhabitat thermal quality will be related to thermal quality in the area.

A Novel Model for Detecting Urban Fringe and Its Expanding Patterns: An Application in Harbin City, China

Urban fringe is an active expanding belt, indicating urban-rural interaction processes. Previous studies have attempted to define urban fringe as the transitional area between urban and rural areas, but there is a lack of quantitative analysis of the periphery boundaries. We developed a novel , the Spatial Segmentation Model (SSM), to detect the extent of urban fringe via calculating the share of the built-up land. Within the urban fringe, we statistically compared the number of built-up patches in each direction and described four urban expanding patterns (stable, sprawling, leaping, and mixing patterns) indicated by the empirical analysis. The results show that this model can reliably detect the urban fringe and could reveal urban growth characteristics. We find the spatial territory changes are highly relative with transport infrastructures in Harbin. Meanwhile, the roads density in the urban core are higher than in the urban fringe. Especially for city roads, roads density in the urban core is more than 4 times higher than in the urban fringe. The growth of the urban fringe is closely related to the development of social economies as well as the space policies and development plans designed by governments. Similar to the post-industry cities worldwide, Harbin should take action to address population decline. Effective land-use and suitable urban growth strategies play an important role in alleviating urban shrinkage. Thus, understanding the dynamics, urban expanding patterns, and driving factors in the urban fringe can help us form a basis for future urban development.

THE ROLE OF THE XAVANTE INDIGENOUS PEOPLE IN WILDLIFE CONSERVATION

There is an urgent demand to evaluate and document the environmental conditions of the territories of indigenous people. This is basic in the efforts to achieve sustainable development goals adopted by all United Nations Member States in 2015. The Xavante people are hunters/gatherers and depend on natural resources for their physical, spiritual, and cultural survival. Their lands are localized in the state of Mato Grosso, Brazil, in a transitional area between the Cerrado vegetation and the Amazon rainforest. They have been developing environmental projects ~in order to manage their territory correctly for decades, as part of their survival strategy. In recent fieldwork, we stated that some major game species may still be abundant in the territory and we suggest that certain wildlife management measures in the past may be responsible for this. We easily registered most game species handled by the Xavantes, except for some edentates that were rarely detected. We confirm the giant anteater as the most vulnerable species to hunting effects. In this article, we point out the main threats for the territory and present new recommendations that may be fundamental for the conservation of biodiversity in the region and the survival of the Xavante people.

A tumor of composite cervical adenocarcinoma with MUCIN gene mutation：a case report

Background : There are reports about the coexistence of two kinds of tumors in the same patient,which is believed that this phenomenon is caused by the dedifferentiation between the two tumors.In this paper, we report an human papillomavirus (HPV) negative cervical adenocarcinoma in a patient composed of two adenocarcinoma components,which is first reported.Histologically, both minimal deviation adenocarcinoma (MDA) and poorly differentiated gastric type adenocarcinoma (GTA) components, as well as their transitional area, were observed.Methods : This case of cervical cancer was screened by gene sequencing. For detection of specific somatic mutations in MDA and GTA, we filtered out mutations in malignant cervical cancer blood sample and 7 common cervical carcinoma. Then the genes were screened and identified based on the enrichment analysis of GO and KEGG and related literature reports. Results : We found 13 specific somatic gene mutations in total. Among these genes, only Mucin gene was transformed from gene level to protein level, and was positive in both MDA and GTA components of the patient by immunohistochemistry.Both components had genes mutation of MUC4 and MUC17,the component in MDA had gene mutation of MUC3A,and we found that MUC3A and MUC17 were on the same chromosome. Moreover,MUC3A and MUC4 genes were found to be fused in FusionGDB database. Conclusion : According to the reports of MUC3A,MUC4 and MUC17 genes mutation in cervical adenocarcinoma and gene fusions in tumorigenesis, we speculate that the occurrence of the transformation of pathological type from MDA to GTA in this case of cervical cancer is related to the mechanism of MUC3A and MUC4 gene fusion.We would advice, for HPV negative or atypical cervical lesions, immunohistochemistry of MUCIN genes staining and gene sequencing should be considered, which may find unusual cancer types and change the prognosis of patients.

Distribution of Sideroxylon Mascatense (A.DC.) T.D.Penn. and Associated Perennial Plant Communities in Oman

BackgroundOman is located on the south-eastern tip of the Arabian Peninsula and is characterized by an arid climate with a vast and varied landscape. Sideroxylon mascatense is a fruit-producing species growing in the arid mountainous regions of North Africa, The Middle East, and Asia. To date, there are no studies describing the population distribution of S. mascatense and the plant communities associated with it in Oman. This study fills this gap.ResultsA series of botanical field surveys was carried out between June 2018 and August 2019 to describe the distribution and associated plant communities of S. mascatense in the Western Hajar Mountains. Sample units were surveyed in the months of June, July, and August as this is the optimal fruiting period of S. mascatense in the Western Hajar Mountains of Oman. Throughout the surveys, 54 perennial non-cultivated species from 32 families were observed growing with S. mascatense. Two-way cluster analysis and indicator species analysis found two main plant communities associated with S. mascatense along an altitudinal gradient. These were the Acridocarpus orientalis-Euphorbia larica community and the Olea europaea-Euryops arabicus community. There was species overlap in the transitional area between the communities where the environmental factors allowed for continuation along the altitudinal gradient. There was no recruitment of S. mascatense observed during the surveys.ConclusionsThe lack of recruitment, along with the threats of overgrazing and habitat destruction, point to an uncertain future for the S. mascatense populations in Oman. As S. mascatense is associated with threatened key species in the Western Hajar Mountains, S. mascatense should be protected and included in conservation projects. This could allow for the establishment of natural recruitment of S. mascatense, thereby preserving the fragile ecosystem of the Western Hajar Mountains and ensuring the future survival of S. mascatense and its associated communities.

Changes of Periphyton Abundance and Biomass Driven by Factors Specific to Flooding Inflow in a River Inlet Area in Erhai Lake, China

Periphyton is an ecological essential in freshwater lakes and rivers. Its abundance and biomass are very dynamic in various habitats and subject to various factors, for example, nutrient and light. Following flooding events, the transitional area adjacent to a river inlet and the shallow lake generates diverse habitats for periphyton with gradients in current velocity, suspended matters, nutrients, and light, which would strongly shape the growth and community of periphyton. In this study, three sampling sites were established around a river inlet in Erhai Lake, China, and a field survey was conducted in the sites from April to August (flooding seasons) in 2019 to investigate the abundance and biomass of periphyton and explore influential factors. The results showed that three study areas have different gradients of current velocity depending on the distance to the river inlet, thereby regulating the concentrations of nutrients and suspended matters, which strongly affected the periphyton community; to be specific, the biomass of periphyton was inhibited by the concentration of suspended matters and high concentrations of silicate mainly reduced the diversity of periphyton. Our results imply that the study on the driving factors of periphyton could help to understand its community assembly mechanism and biomass and species composition of periphyton can provide some reference for trophic state of the lake.

A Tumor of Composite Cervical Adenocarcinoma with MUCIN Gene Mutation：A Case Report

Background:There are reports about the coexistence of two kinds of tumors in the same patient,which is believed that this phenomenon is caused by the dedifferentiation between the two tumors.In this paper, we report an human papillomavirus (HPV) negative cervical adenocarcinoma in a patient composed of two adenocarcinoma components,which is first reported.Histologically, both minimal deviation adenocarcinoma (MDA) and poorly differentiated gastric type adenocarcinoma (GTA) components, as well as their transitional area, were observed.Methods:This case of cervical cancer was screened by gene sequencing. For detection of specific somatic mutations in MDA and GTA, we filtered out mutations in malignant cervical cancer blood sample and 7 common cervical carcinoma. Then the genes were screened and identified based on the enrichment analysis of GO and KEGG and related literature reports. Results:We found 13 specific somatic gene mutations in total. Among these genes, only Mucin gene was transformed from gene level to protein level, and was positive in both MDA and GTA components of the patient by immunohistochemistry.Both components had genes mutation of MUC4 and MUC17,the component in MDA had gene mutation of MUC3A,and we found that MUC3A and MUC17 were on the same chromosome. Moreover,MUC3A and MUC4 genes were found to be fused in FusionGDB database. Conclusion:According to the reports of MUC3A,MUC4 and MUC17 genes mutation in cervical adenocarcinoma and gene fusions in tumorigenesis, we speculate that the occurrence of the transformation of pathological type from MDA to GTA in this case of cervical cancer is related to the mechanism of MUC3A and MUC4 gene fusion.We would advice, for HPV negative or atypical cervical lesions, immunohistochemistry of MUCIN genes staining and gene sequencing should be considered, which may find unusual cancer types and change the prognosis of patients.