Some observations on Spanner's conception of the placental vascular arrangement and the maternal blood circulation through it

While the development of the vascular system in other organs is regulated by functional influences and hereditary factors; in the case of the placenta the site of implantation in the uterus and the characteristics of the maternal circulation also play an important role. The maternal and foetal blood circulatory paths within the placenta are regarded from the haemodynamic point of view as most complicated because the placental structure is looked upon as being most complex. Many contradicting views are held in that respect and many theories are formulated regarding the placental structure and maternal blood circulation through it. It is clear that in order to understand these questions the placental connections with the uterus and foetus must be studied both with the naked eye and microscope. The human placenta according to Grosser is described as a placenta haemochorialis, thereby meaning that the foetal chorion is in direct relationship with the maternal blood. This fact underlies many risks that the pregnant, parturient, and puerperal woman undergoes and it follows that a sound knowledge of the vascular conditions in the pregnant uterus underlies the pathology of reproduction. For instance: is the mechanism of antepartum and postpartum haemorrhage really understood? or the factors that are associated with embolus complicating child birth known? - advancement in obstetrics depends to some extent on the complete knowledge of this subject. In 1935 Rudolf Spanner of Kiel brought forward a new conception formulating a new idea not only of the structure of the placenta but of the circulation of the maternal blood through that organ and back to the uterine veins. His work depended on injection experiments on the pregnant uterus and placenta. In the present scope of this work Spanner's work on the subject has been studied and experiments done to compare with his results

Positive Solutions for Boundary Value Problem of Nonlinear Fractional Differential Equation

We are concerned with the existence and nonexistence of positive solutions for the nonlinear fractional boundary value problem: D0+αu(t)+λa(t) f(u(t))=0, 0<t<1,  u(0)=u′(0)=u′(1)=0, where 2<α<3 is a real number and D0+α is the standard Riemann-Liouville fractional derivative. Our analysis relies on Krasnoselskiis fixed point theorem of cone preserving operators. An example is also given to illustrate the main results

The Fractional SIRC Model and Influenza A

This paper deals with the fractional-order SIRC model associated with the evolution of influenza A disease in human population. Qualitative dynamics of the model is determined by the basic reproduction number, 0. We give a detailed analysis for the asymptotic stability of disease-free and positive fixed points. Nonstandard finite difference methods have been used to solve and simulate the system of differential equations

Existence of Positive Solutions for m-Point Boundary Value Problem for Nonlinear Fractional Differential Equation

We investigate an m-point boundary value problem for nonlinear fractional differential equations. The associated Green function for the boundary value problem is given at first, and some useful properties of the Green function are obtained. By using the fixed point theorems of cone expansion and compression of norm type and Leggett-Williams fixed point theorem, the existence of multiple positive solutions is obtained

Derivative-order-dependent stability and transient behaviour in a predator–prey system of fractional differential equations

In this paper, the static and dynamic behaviour of a fractional-order predator–prey model are studied, where the nonlinear interactions between the two species lead to multiple stable states. As has been found in many previous systems, the stability of such states can be dependent on the fractional order of the time derivative, which is included as a phenomenological model of memory-effects in the predator and prey species. However, what is less well understood is the transient behaviour and dependence of the observed domains of attraction for each stable state on the order of the fractional time derivative. These dependencies are investigated using analytical (for the stability of equilibria) and numerical (for the observed domains of attraction) techniques. Results reveal far richer dynamics compared to the integer-order model. We conclude that, as well as the species and controllable parameters, the memory effect of the species will play a role in the observed behaviour of the system

Retrograde Pedal Access For Revascularization Of Infrapopliteal Arterial Occlusive Disease In Critical Limb Ischemia (CLI) Patients As A Primary Approach.

Introduction: We are presenting three cases (out of similar several cases) where tibio-pedal approach was performed as an initial primary approach for limb salvage in patients with CLI secondary to Infra-popliteal (IP) disease. We consider this approach to be a necessary evolution in endovascular intervention. Discussion: Retrograde pedal access is safe, feasible with high technical success rate and a relatively low procedural complication rate, with low 30 days mortality and low rate of major adverse cardiac events. Freedom from major adverse limb events and limb salvage are both high at 1 year follow up. It allows quick therapy and short procedure time with less observation time in the hospital. A retrograde approach utilizing pedal access improves the crossing success of lesions as well as facilitates the use of some atherectomy devices to remove large plaque burden and modify the compliance of severely calcified infra-popliteal vessels. Using the retrograde approach will minimize the classic complications of the antegrade femoral approach. Conclusion: Retrograde tibio-pedal arterial access, as an initial primary approach for endovascular intervention in CLI patients confined to IP vessels, is an effective, safe, and feasible approach with a high technical success rate and a relatively low procedural complication rate

On fractional order dengue epidemic model

This paper deals with the fractional order dengue epidemic model. The stability of disease-free and positive fixed points is studied. Adams-Bashforth-Moulton algorithm has been used to solve and simulate the system of differential equations.This project was funded by the Deanship of Scientific Research (DSR), King Abdulaziz University, under Grant no. 3-130/1433HiCiS

Morphological and molecular characterization of somaclonal variations in tissue culture-derived banana plants

AbstractIn this study, 40000 tissue culture-derived banana plants (vitroplants) at different growth stages, i.e. acclimatization, nursery and open field of banana (Musa spp.) cultivar ‘Grand Naine’ were screened for somaclonal variations using morphological investigations and molecular characterization. The total detected variants were grouped into 25 off-types (two of them died) in addition to the normal plant. Random Amplified Polymorphic DNA (RAPD) was carried out to study the differences among the normal cultivar ‘Grand Naine’ and its 23 variants using 17 arbitrary primers. Cluster analysis results revealed that ‘winged petiole’ and ‘deformed lamina’ were more related to the normal plant. However, ‘Giant plant’ and ‘weak plant’ related to each other and clustered with normal plant. According to principal coordinate analysis, most of the variants were aggregated nearly, whereas ‘variegated plant’ was separated apart from the other variants. This may reflect the genetic difference between ‘variegated plant’ and the other variants. The results obtained from both molecular and morphological analyses were in contiguous with better resolution when using the PCOORDA analysis than cluster analysis. Thus, it can be said that molecular markers can be used to eliminate the undesirable somaclonal variants from the lab without additional culture of the vitroplants in the field in order to save time and efforts

DIALLEL ANALYSIS AMONG NEW YELLOW MAIZE INBRED LINES FOR GRAIN YIELD AND OTHER AGRONOMIC TRAITS

Yellow maize ( Zea mays L.) is one of the important sources of animal feed in Egypt. The national maize programmes uses conventional crop breeding methodology, which depends on the development inbred lines of maize from open pollinated varieties or other heterogeneous sources. The objective of this study was to assess the general and specific combining ability for nine yellow maize inbred lines and their crosses for grain yield and other morphological traits, under Egyptian conditions. Nine new yellow maize inbred lines, derived from different yellow maize sources, were crossed in a half diallel mating scheme in 2020 summer season, at Gemmeiza Agricultural Research Station Gharbia Governorate in Egypt. The resulting 36 crosses, along with two commercial check hybrids (SC 168 and Pioneer SC 3444), were evaluated at three locations, i.e. Gemmeiza, Mallawy and Sids Agricultural Research Stations of the Agricultural Research Center (ARC), in 2021 summer season in Egypt. Overall, the additive gene effects played a major role in the inheritance of days to 50% silking, plant and ear heights; while the non-additive gene effects were mostly responsible for controlling the inheritance of grain yield. The parental inbred lines (P1 and P2) possessed significant (P&lt;0.05) negative estimates of GCA effects for days to 50% silking towards earliness. The best general combiners were inbred lines P2 and P6 for plant and ear height, and these inbred lines would be good combiners for breeding to short hybrids and low ear placement. Crosses (P1xP9 and P3xP4) had desirable SCA effects and significantly out-yielded the two checks.Le ma\uefs jaune (Zea mays L.) est l\u2019une des principales sources d\u2019alimentation animale en \uc9gypte. Les programmes nationaux de ma\uefs utilisent une m\ue9thodologie conventionnelle de s\ue9lection des cultures, qui d\ue9pend du d\ue9veloppement de lign\ue9es consanguines de ma\uefs \ue0 partir de vari\ue9t\ue9s \ue0 pollinisation libre ou d\u2019autres sources h\ue9t\ue9rog\ue8nes. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer la capacit\ue9 de combinaison g\ue9n\ue9rale et sp\ue9cifique de neuf lign\ue9es consanguines de ma\uefs jaune et de leurs croisements pour le rendement en grain et d\u2019autres caract\ue8res morphologiques, dans les conditions \ue9gyptiennes. Neuf nouvelles lign\ue9es consanguines de ma\uefs jaune, d\ue9riv\ue9es de diff\ue9rentes sources de ma\uefs jaune, ont \ue9t\ue9 crois\ue9es dans un sch\ue9ma d\u2019accouplement semi-diall\ue8le au cours de la saison estivale 2020, \ue0 la station de recherche agricole de Gemmeiza, dans le gouvernorat de Gharbia, en \uc9gypte. Les 36 croisements r\ue9sultants, ainsi que deux hybrides t\ue9moins commerciaux (SC 168 et Pioneer SC 3444), ont \ue9t\ue9 \ue9valu\ue9s \ue0 trois endroits, \ue0 savoir les stations de recherche agricole de Gemmeiza, Mallawy et Sids du Centre de recherche agricole (ARC), au cours de la saison estivale 2021 en \uc9gypte. Dans l\u2019ensemble, les effets additifs des g\ue8nes ont jou\ue9 un r\uf4le majeur dans l\u2019h\ue9r\ue9dit\ue9 des jours \ue0 50\ua0% d\u2019apparition des soies, des hauteurs de plantes et d\u2019\ue9pis\ua0; tandis que les effets g\ue9n\ue9tiques non additifs \ue9taient principalement responsables du contr\uf4le de l\u2019h\ue9r\ue9dit\ue9 du rendement en grain. Les lign\ue9es consanguines parentales (P1 et P2) poss\ue9daient des estimations n\ue9gatives significatives (P &lt;0,05) des effets de la GCA pendant des jours jusqu\u2019\ue0 50\ua0% de soyage vers la pr\ue9cocit\ue9. Les meilleurs combineurs g\ue9n\ue9raux \ue9taient les lign\ue9es consanguines P2 et P6 pour la hauteur des plantes et des \ue9pis, et ces lign\ue9es consanguines seraient de bons combinateurs pour la reproduction d\u2019hybrides courts et le placement des oreilles basses. Les croisements (P1xP9 et P3xP4) ont eu des effets SCA souhaitables et ont nettement d\ue9pass\ue9 les deux contr\uf4les