Bone is a highly vascularized tissue reliant on the close spatial and temporal association between bloodvessels and bone cells. Therefore, cells that participate in vasculogenesis and osteogenesis play a pivotal role ...Bone is a highly vascularized tissue reliant on the close spatial and temporal association between bloodvessels and bone cells. Therefore, cells that participate in vasculogenesis and osteogenesis play a pivotal role in bone formation during prenatal and postnatal periods. Nevertheless, spontaneous healing of bone fracture is occasionally impaired due to insufficient blood and cellular supply to the site of injury. In these cases, bone regeneration process is interrupted, which might result in delayed union or even nonunion of the fracture. Nonunion fracture is difficult to treat and have a high financial impact. In the last decade, numerous technological advancements in bone tissue engineering and cell-therapy opened new horizon in the field of bone regeneration. This review starts with presentation of the biological processes involved in bone development, bone remodeling, fracture healing process and the microenvironment at bone healing sites. Then, we discuss the rationale for using adult stem cells and listed the characteristics of the available cells for bone regeneration. The mechanism of action and epigenetic regulations for osteogenic differentiation are also described. Finally, we review the literature for translational and clinical trials that investigated the use of adult stem cells(mesenchymal stem cells, endothelial progenitor cells and CD34+ blood progenitors) for bone regeneration.展开更多
Vitamin D is known to be a key regulator of bone metabolism and is associated with muscle strength.Vitamin D deficiency is widely prevalent worldwide.In adults,vitamin D deficiency has been implicated in numerous heal...Vitamin D is known to be a key regulator of bone metabolism and is associated with muscle strength.Vitamin D deficiency is widely prevalent worldwide.In adults,vitamin D deficiency has been implicated in numerous health conditions including osteoporosis,cancer,diabetes,and autoimmune diseases.Considerable changes have occurred in lifestyles and childhood activities in the past years.Studies have shown that the children population is at high risks of vitamin D deficiency.The objective of this study was to learn about the extent of vitamin D deficiency in children worldwide and especially in sunny country like Israel.In this article we reviewed the extent and severity of vitamin D deficiency worldwide and especially in Israel,through a very comprehensive review of previous reports and research studies done during the last years.We found reports on vitamin D deficiency in children,which was associated with metabolic syndromes and obesity.It was more prevalent in children who spend less time on outdoor activities,in obese children,and in cases when there was imbalance between nutritional intakes and requirements.Vitamin D deficiency is common even in children living in sunny places like Israel.Health professionals should be aware of the fact that although vitamin D deficiency is prevalent in the elderly population,it is also common in children,and can be associated with different illnesses.We encourage supplementation of vitamin D to special populations(pregnant and lactating women,infants,and high risk groups).We also encourage implementation of international food fortification programs.展开更多
The idea that approximate exactness is the most we can and should expect scientific theories to yield underlies the formation and application of the multi-valued logic of approximation discussed in this paper. In this...The idea that approximate exactness is the most we can and should expect scientific theories to yield underlies the formation and application of the multi-valued logic of approximation discussed in this paper. In this logic, inexactness （measured by truth values） is controlled and minimized by means of uniquely designed deductions. We show how the notion of equality （including substitution of equals） is handled within this logic and we apply it to certain principles and interpretations of quantum theory.展开更多
Democratic private schools in Israel are a part of the neo-liberal discourse. They champion the dialogic philosophy associated with its most prominent advocates--Martin Buber, Emmanuel Levinas---together with Paulo Fr...Democratic private schools in Israel are a part of the neo-liberal discourse. They champion the dialogic philosophy associated with its most prominent advocates--Martin Buber, Emmanuel Levinas---together with Paulo Freire＇s critical pedagogy, the humanistic psychology propounded by Carl Rogers, Nel Noddings＇s pedagogy of care and concern, and even Gadamer＇s integrative hermeneutic perspective. Democratic schools form one of the greatest challenges to State education and most vocal and active critique of the focus conservative education places on exams and achievement. This article describes the dual discourse connected to the schools. The first is the inner dialogical, which is devoted to student freedom and progress, the child being placed at the center. The second is the exterior discourse, which represents the school as a place of counter-education that provides personal and group development and comprises a site of liberty and choice. The schools in Israel are described as test case and indicating the existence of a sophisticated form of deception via the use of alluring terminology. The democratic private schools should be recognized for what they really are--agents of commodification that undermine democracy rather than enhance it.展开更多
We propose a novel model, based on two postulates, which provide new perspective on the fundamental forces using special and general relativity concepts. Many studies address the relations between the particles and th...We propose a novel model, based on two postulates, which provide new perspective on the fundamental forces using special and general relativity concepts. Many studies address the relations between the particles and the space time manifold, and the latter＇s physical structure, whether it is Continuous or Discrete. In the proposed model the properties of the particles are classical in the sense of general relativity, whereas their quantum properties are arises due to the experiments.展开更多
Delayed selfing could provide ovules with an opportunity to be fertilized as a means of"pollination assurance"before the flowers wilt.It could,thus,be regarded as an adaptation to unpredictable pollinator en...Delayed selfing could provide ovules with an opportunity to be fertilized as a means of"pollination assurance"before the flowers wilt.It could,thus,be regarded as an adaptation to unpredictable pollinator environments.Within the alpine biennial Gentianopsis paludosa,the showy flowers and herkogamy at the early stage of a flower's life cycle may favor outcrossing.As the flower ages,anthers contact the central stigma due to the elongation of all filaments,resulting in autonomous selfing.Flower visitors are extremely rare in a high altitude population;and examination of the mating system indicates that G.paludosa is self-pollinated under natural conditions in this population.While at the lower altitude,the bumblebee visitation rate is relatively high but possibly unreliable.Stigma receptivity is the highest on the third day of anthesis,and decreases thereafter.Pollen viability is the highest when flowers open,and gradually decreases later.Self-pollination of G.paludosa occurs at the late stage of a flower's lifecycle when stigma receptivity and pollen viability have both decreased,suggesting delayed selfing and assurance of seed production.This delayed selfing could assure seed production under the constraints of pollinator scarcity,but ensure outcrossing when pollinators were available.Such a flexible pollination mechanism is highly adaptive in the alpine environment of the Qinghai-Tibetan Plateau.展开更多
Let Dn be the set of all signed permutations on n = {1,...,n} with even signs,and let Dn(T) be the set of all signed permutations in Dn which avoids a set T of signed patterns.In this paper,we find all the cardinaliti...Let Dn be the set of all signed permutations on n = {1,...,n} with even signs,and let Dn(T) be the set of all signed permutations in Dn which avoids a set T of signed patterns.In this paper,we find all the cardinalities of the sets Dn(T) where T■B2.Some of the cardinalities encountered involve inverse binomial coefficients,binomial coefficients,Catalan numbers,and Fibonacci numbers.展开更多
文摘Bone is a highly vascularized tissue reliant on the close spatial and temporal association between bloodvessels and bone cells. Therefore, cells that participate in vasculogenesis and osteogenesis play a pivotal role in bone formation during prenatal and postnatal periods. Nevertheless, spontaneous healing of bone fracture is occasionally impaired due to insufficient blood and cellular supply to the site of injury. In these cases, bone regeneration process is interrupted, which might result in delayed union or even nonunion of the fracture. Nonunion fracture is difficult to treat and have a high financial impact. In the last decade, numerous technological advancements in bone tissue engineering and cell-therapy opened new horizon in the field of bone regeneration. This review starts with presentation of the biological processes involved in bone development, bone remodeling, fracture healing process and the microenvironment at bone healing sites. Then, we discuss the rationale for using adult stem cells and listed the characteristics of the available cells for bone regeneration. The mechanism of action and epigenetic regulations for osteogenic differentiation are also described. Finally, we review the literature for translational and clinical trials that investigated the use of adult stem cells(mesenchymal stem cells, endothelial progenitor cells and CD34+ blood progenitors) for bone regeneration.
文摘Vitamin D is known to be a key regulator of bone metabolism and is associated with muscle strength.Vitamin D deficiency is widely prevalent worldwide.In adults,vitamin D deficiency has been implicated in numerous health conditions including osteoporosis,cancer,diabetes,and autoimmune diseases.Considerable changes have occurred in lifestyles and childhood activities in the past years.Studies have shown that the children population is at high risks of vitamin D deficiency.The objective of this study was to learn about the extent of vitamin D deficiency in children worldwide and especially in sunny country like Israel.In this article we reviewed the extent and severity of vitamin D deficiency worldwide and especially in Israel,through a very comprehensive review of previous reports and research studies done during the last years.We found reports on vitamin D deficiency in children,which was associated with metabolic syndromes and obesity.It was more prevalent in children who spend less time on outdoor activities,in obese children,and in cases when there was imbalance between nutritional intakes and requirements.Vitamin D deficiency is common even in children living in sunny places like Israel.Health professionals should be aware of the fact that although vitamin D deficiency is prevalent in the elderly population,it is also common in children,and can be associated with different illnesses.We encourage supplementation of vitamin D to special populations(pregnant and lactating women,infants,and high risk groups).We also encourage implementation of international food fortification programs.
文摘The idea that approximate exactness is the most we can and should expect scientific theories to yield underlies the formation and application of the multi-valued logic of approximation discussed in this paper. In this logic, inexactness （measured by truth values） is controlled and minimized by means of uniquely designed deductions. We show how the notion of equality （including substitution of equals） is handled within this logic and we apply it to certain principles and interpretations of quantum theory.
文摘Democratic private schools in Israel are a part of the neo-liberal discourse. They champion the dialogic philosophy associated with its most prominent advocates--Martin Buber, Emmanuel Levinas---together with Paulo Freire＇s critical pedagogy, the humanistic psychology propounded by Carl Rogers, Nel Noddings＇s pedagogy of care and concern, and even Gadamer＇s integrative hermeneutic perspective. Democratic schools form one of the greatest challenges to State education and most vocal and active critique of the focus conservative education places on exams and achievement. This article describes the dual discourse connected to the schools. The first is the inner dialogical, which is devoted to student freedom and progress, the child being placed at the center. The second is the exterior discourse, which represents the school as a place of counter-education that provides personal and group development and comprises a site of liberty and choice. The schools in Israel are described as test case and indicating the existence of a sophisticated form of deception via the use of alluring terminology. The democratic private schools should be recognized for what they really are--agents of commodification that undermine democracy rather than enhance it.
文摘We propose a novel model, based on two postulates, which provide new perspective on the fundamental forces using special and general relativity concepts. Many studies address the relations between the particles and the space time manifold, and the latter＇s physical structure, whether it is Continuous or Discrete. In the proposed model the properties of the particles are classical in the sense of general relativity, whereas their quantum properties are arises due to the experiments.
基金support by the Chinese Academy of Sciences(Key Innovation Plan KSCX-SW2-106 and the Special Fund for Outstanding PhD Dissertations to Jian-Quan Liu)the National Natural Science Foundation of China(30270253and 30700096)
文摘Delayed selfing could provide ovules with an opportunity to be fertilized as a means of"pollination assurance"before the flowers wilt.It could,thus,be regarded as an adaptation to unpredictable pollinator environments.Within the alpine biennial Gentianopsis paludosa,the showy flowers and herkogamy at the early stage of a flower's life cycle may favor outcrossing.As the flower ages,anthers contact the central stigma due to the elongation of all filaments,resulting in autonomous selfing.Flower visitors are extremely rare in a high altitude population;and examination of the mating system indicates that G.paludosa is self-pollinated under natural conditions in this population.While at the lower altitude,the bumblebee visitation rate is relatively high but possibly unreliable.Stigma receptivity is the highest on the third day of anthesis,and decreases thereafter.Pollen viability is the highest when flowers open,and gradually decreases later.Self-pollination of G.paludosa occurs at the late stage of a flower's lifecycle when stigma receptivity and pollen viability have both decreased,suggesting delayed selfing and assurance of seed production.This delayed selfing could assure seed production under the constraints of pollinator scarcity,but ensure outcrossing when pollinators were available.Such a flexible pollination mechanism is highly adaptive in the alpine environment of the Qinghai-Tibetan Plateau.
基金The National Natural Science Foundation of China （No. 10801020）.
文摘Let Dn be the set of all signed permutations on n = {1,...,n} with even signs,and let Dn(T) be the set of all signed permutations in Dn which avoids a set T of signed patterns.In this paper,we find all the cardinalities of the sets Dn(T) where T■B2.Some of the cardinalities encountered involve inverse binomial coefficients,binomial coefficients,Catalan numbers,and Fibonacci numbers.
