In an environment where demand for housing is growing and the supply from public authorities is virtually non-existent,several mechanisms for housing production are emerging in the formal,semi-informal and informal co...In an environment where demand for housing is growing and the supply from public authorities is virtually non-existent,several mechanisms for housing production are emerging in the formal,semi-informal and informal construction sectors.The project owner wonders how much it costs to construct a building to an acceptable standard.Cost forecasting in general faces a number of difficulties,including a lack of available information during the preliminary phase of the project.As such,estimation becomes a crucial task involving great responsibility,which can lead to either more convincing results or chaotic situations.This study proposes a quick and effective method for estimating the cost of a single-storey F4 residential building.The modelling is done using multiple linear regression based on a statistical approach applied to twenty(20)projects that have already been completed.The project data are collected from design offices in the city of Brazzaville.The method expresses the cost of an F4 construction by certain project tasks,representing five(5)variables,three(3)of which are related to structural work and two(2)to finishing work,which are easy to determine.This approach,known as MECSO(Cost Estimation Model by Sub-structure),gives good results in all statistical tests carried out with reasonable confidence intervals.This method is very practical for engineering professionals working on the evaluation and control of construction costs.展开更多
UGT(UDP-dependent glycosyltransferase)family members are mainly involved in the modification of secondary metabolites,as well as plant stress responses.Previously,we identified the UGT gene MdUGT88F4 from Malus spp.In...UGT(UDP-dependent glycosyltransferase)family members are mainly involved in the modification of secondary metabolites,as well as plant stress responses.Previously,we identified the UGT gene MdUGT88F4 from Malus spp.In order to verify whether it had biological function in apple plants,we generated transgenic apple plants overexpressed MdUGT88F4 and treated them with salt stress.The results showed that it conferred enhanced salt stress tolerance in transgenic‘GL-3’apple(Malus domestica)plants.The expression of MdUGT88F4 was induced by salt stress,and overexpression of this gene alleviated the inhibitory effects of salt stress on the growth of apple plants.After 15 days of salt stress treatment(100 mmol·L^(-1)NaCl),necrotic spots were present on the leaves of wild-type(WT)plants,and none were observed on the leaves of transgenic plants overexpressing MdUGT88F4(OX).The relative electrolyte leakage and malondialdehyde content were lower and the total chlorophyll content and the relative water content were higher in OX plants than in WT plants.The photosynthetic efficiency was higher in OX plants than in WT plants under salt stress,which was consistent with their larger stomatal aperture;this might stem from a reduction in the content of abscisic acid.The production of reactive oxygen species was lower and the activities of antioxidant enzymes were higher in OX plants than in WT plants.In addition,OX plants accumulated less Na^(+)but more K^(+)than WT plants,and the expression of several genes involved in Na^(+)transport was upregulated in OX plants.MdUGT88F4 failed to promote the accumulation of isosalipurposide in vivo,and it was involved in isosalipurposide synthesis.Most of the flavonoid metabolites accumulated to a greater degree in OX plants than in WT plants.In summary,our results show that MdUGT88F4 positively regulates the salt stress response in apple plants,possibly by affecting stomatal movement,as well as the accumulation of ions and flavonoids.Our findings enhance our understanding of the metabolic mechanisms by which UGT proteins ameliorate the effects of salt stress in plants.展开更多
Hearing relies on the structural and functional integrity of cochlear hair cells,particularly their apical F-actin-filled stereocilia.Phospholipid scramblases are important for maintaining membrane asymmetry,but their...Hearing relies on the structural and functional integrity of cochlear hair cells,particularly their apical F-actin-filled stereocilia.Phospholipid scramblases are important for maintaining membrane asymmetry,but their roles in the stereocilia and auditory functions are not fully understood.Here,we identify Plscr5 as a downstream target of the transcription factor POU4F3 essential for hair cell function,whose mutation causes human DFNA15 deafness.Plscr5 knockout mice exhibit progressive hearing loss due to stereocilia degeneration and hair cell loss.Functional analyses reveal that PLSCR5 contributes to phosphatidylserine externalization in hair cell apical membranes,particularly in inner hair cells,and is important for outer hair cell and stereocilia maintenance.Our findings highlight PLSCR5 as an important downstream effector of POU4F3 and regulator of phosphatidylserine externalization and membrane dynamics required for auditory functions.展开更多
本文从分析目前研学实践活动开展所存在的问题出发,提出将4F教学模式融入研学实践活动方案设计的优势,并以内蒙古集宁区霸王河国家湿地公园为例,确立基于地理学科核心素养的研学目标,依据4F教学模式的四个阶段设计研学活动实施过程,同...本文从分析目前研学实践活动开展所存在的问题出发,提出将4F教学模式融入研学实践活动方案设计的优势,并以内蒙古集宁区霸王河国家湿地公园为例,确立基于地理学科核心素养的研学目标,依据4F教学模式的四个阶段设计研学活动实施过程,同时制定了基于4F模式的评价量表,对学生的研学过程与研学结果进行全方位多角度评价,以期提高研学效果,为相关研究者和一线地理教师更好地设计基于4F模式的研学实践活动方案提供参考。Based on the analysis of the existing problems in the development of current research practice activities, this paper proposes the advantages of integrating 4F teaching mode into the design of research practice activities. Taking Bawanghe National Wetland Park in Jining District, Inner Mongolia as an example, this paper establishes research objectives based on the core accomplishment of geography, and designs the implementation process of research activities according to the four stages of 4F teaching mode. At the same time, an evaluation scale based on 4F model is developed to evaluate students’ research process and research results from a comprehensive and multi-angle, in order to improve the research effect and provide references for relevant researchers and front-line geography teachers to better design research practice activities based on 4F model.展开更多
文摘In an environment where demand for housing is growing and the supply from public authorities is virtually non-existent,several mechanisms for housing production are emerging in the formal,semi-informal and informal construction sectors.The project owner wonders how much it costs to construct a building to an acceptable standard.Cost forecasting in general faces a number of difficulties,including a lack of available information during the preliminary phase of the project.As such,estimation becomes a crucial task involving great responsibility,which can lead to either more convincing results or chaotic situations.This study proposes a quick and effective method for estimating the cost of a single-storey F4 residential building.The modelling is done using multiple linear regression based on a statistical approach applied to twenty(20)projects that have already been completed.The project data are collected from design offices in the city of Brazzaville.The method expresses the cost of an F4 construction by certain project tasks,representing five(5)variables,three(3)of which are related to structural work and two(2)to finishing work,which are easy to determine.This approach,known as MECSO(Cost Estimation Model by Sub-structure),gives good results in all statistical tests carried out with reasonable confidence intervals.This method is very practical for engineering professionals working on the evaluation and control of construction costs.
基金supported by the Natural Science Basic Research Program of Shaanxi(Grant No.2023-JC-YB-170)the earmarked fund for the China Agricultural Research System(Grant No.CARS-27)the Key S&T Special Projects of Shannxi Province(Grant No.2020zdzx03-01-02)。
文摘UGT(UDP-dependent glycosyltransferase)family members are mainly involved in the modification of secondary metabolites,as well as plant stress responses.Previously,we identified the UGT gene MdUGT88F4 from Malus spp.In order to verify whether it had biological function in apple plants,we generated transgenic apple plants overexpressed MdUGT88F4 and treated them with salt stress.The results showed that it conferred enhanced salt stress tolerance in transgenic‘GL-3’apple(Malus domestica)plants.The expression of MdUGT88F4 was induced by salt stress,and overexpression of this gene alleviated the inhibitory effects of salt stress on the growth of apple plants.After 15 days of salt stress treatment(100 mmol·L^(-1)NaCl),necrotic spots were present on the leaves of wild-type(WT)plants,and none were observed on the leaves of transgenic plants overexpressing MdUGT88F4(OX).The relative electrolyte leakage and malondialdehyde content were lower and the total chlorophyll content and the relative water content were higher in OX plants than in WT plants.The photosynthetic efficiency was higher in OX plants than in WT plants under salt stress,which was consistent with their larger stomatal aperture;this might stem from a reduction in the content of abscisic acid.The production of reactive oxygen species was lower and the activities of antioxidant enzymes were higher in OX plants than in WT plants.In addition,OX plants accumulated less Na^(+)but more K^(+)than WT plants,and the expression of several genes involved in Na^(+)transport was upregulated in OX plants.MdUGT88F4 failed to promote the accumulation of isosalipurposide in vivo,and it was involved in isosalipurposide synthesis.Most of the flavonoid metabolites accumulated to a greater degree in OX plants than in WT plants.In summary,our results show that MdUGT88F4 positively regulates the salt stress response in apple plants,possibly by affecting stomatal movement,as well as the accumulation of ions and flavonoids.Our findings enhance our understanding of the metabolic mechanisms by which UGT proteins ameliorate the effects of salt stress in plants.
基金supported by the National Natural Science Foundation of China(82171136 and 92368110 to G.W.,82201291 to G.-J.Z.,82192861 to Z.X.,81970884 and 82192862 to X.G.)the Natural Science Foundation of Jiangsu Province(BK20220188 to Q.L.,BK20220189 to G.-J.Z.)the Fundamental Research Funds for the Central Universities(021414380533 to G.W.).
文摘Hearing relies on the structural and functional integrity of cochlear hair cells,particularly their apical F-actin-filled stereocilia.Phospholipid scramblases are important for maintaining membrane asymmetry,but their roles in the stereocilia and auditory functions are not fully understood.Here,we identify Plscr5 as a downstream target of the transcription factor POU4F3 essential for hair cell function,whose mutation causes human DFNA15 deafness.Plscr5 knockout mice exhibit progressive hearing loss due to stereocilia degeneration and hair cell loss.Functional analyses reveal that PLSCR5 contributes to phosphatidylserine externalization in hair cell apical membranes,particularly in inner hair cells,and is important for outer hair cell and stereocilia maintenance.Our findings highlight PLSCR5 as an important downstream effector of POU4F3 and regulator of phosphatidylserine externalization and membrane dynamics required for auditory functions.
文摘本文从分析目前研学实践活动开展所存在的问题出发,提出将4F教学模式融入研学实践活动方案设计的优势,并以内蒙古集宁区霸王河国家湿地公园为例,确立基于地理学科核心素养的研学目标,依据4F教学模式的四个阶段设计研学活动实施过程,同时制定了基于4F模式的评价量表,对学生的研学过程与研学结果进行全方位多角度评价,以期提高研学效果,为相关研究者和一线地理教师更好地设计基于4F模式的研学实践活动方案提供参考。Based on the analysis of the existing problems in the development of current research practice activities, this paper proposes the advantages of integrating 4F teaching mode into the design of research practice activities. Taking Bawanghe National Wetland Park in Jining District, Inner Mongolia as an example, this paper establishes research objectives based on the core accomplishment of geography, and designs the implementation process of research activities according to the four stages of 4F teaching mode. At the same time, an evaluation scale based on 4F model is developed to evaluate students’ research process and research results from a comprehensive and multi-angle, in order to improve the research effect and provide references for relevant researchers and front-line geography teachers to better design research practice activities based on 4F model.
