Some factors affecting production and milk composition characters in a crossbreeding experiment involving Gabali and V- line rabbits in Egypt

[EN] Data from 662 litters and 221 samples (two replicates per each sample) of rabbit milk were collectedfrom three different genetic groups [Gabali (G), V-line (V) and GxV (F1)] to study the effect of line and of somenon-genetic factors affecting production and milk composition traits. The studied traits were: number bornalive (LSBA); litter size at weaning (LSW); litter weight born alive (LWBA); litter weight at weaning (LWW); totalmilk yield (TMY) and protein, fat, total solids (TS), ash, phosphorus (P), potassium (K), sodium (Na), calcium(Ca) and magnesium (Mg) milk content. The genetic group effect was significant for LSBA [V (7.3) and F1(7.3)were superior to G (6.6)); LWBA (higher values for V (416 g) and F1 (405 g) than for G (382 g)]; TMY [G (3497g) and F1(3486 g) higher than V (3042 g)]; milk fat [F1 (26%) and G (25%) superior to V (23%)] and milkTS[F1(42%) superior to G (40%) and V (39%)]. The estimates of the heterosis effect ranged between 1.6% and12.8% for production and milk gross chemical traits, being significant only for milk fat content (9.1%). Thepositive values of the heterosis estimates for those traits and the complementarity between the G breed andthe V line, the G superior in milk related traits but the V superior in prolificacy, show the interest of their crossand of the synthetic lines derived from them. The heterosis was non-significant for milk mineral content traits.The parity effects were significant for LSBA, fat, TS, ash and K (the maxima were reached at 6th or 5th parity).The effect of week of lactation was significant for fat, ash and TS, corresponding the maximum values of fatand TS to the 3rd and 4th week. The year-season or the year-month effects were significant for all traitsshowing the importance of including these time-period factors into the statistical models proposed for thetraits.This project was supported by the Spanish Agency of International Cooperation (A.E.C.I.) and the Center of Cooperation for Development of the Universidad Politécnica de Valencia, Spain. We, also, appreciate the effort of Prof. Dr. Maher Khalil supporting the project.Iraqi, M.; Shenana, M.; Baselga, M. (2007). Some factors affecting production and milk composition characters in a crossbreeding experiment involving Gabali and V- line rabbits in Egypt. World Rabbit Science. 15(3). doi:10.4995/wrs.2007.594SWORD15

A mini review on the development of conjugated polymers: steps towards the commercialization of organic solar cells

This review article covers the synthesis and design of conjugated polymers for carefully adjusting energy levels and energy band gap (EBG) to achieve the desired photovoltaic performance. The formation of bonds and the delocalization of electrons over conjugated chains are both explained by the molecular orbital theory (MOT). The intrinsic characteristics that classify conjugated polymers as semiconducting materials come from the EBG of organic molecules. A quinoid mesomeric structure (D-A ↔ D+ = A−) forms across the major backbones of the polymer as a result of alternating donor–acceptor segments contributing to the pull–push driving force between neighboring units, resulting in a smaller optical EBG. Furthermore, one of the most crucial factors in achieving excellent performance of the polymer is improving the morphology of the active layer. In order to improve exciton diffusion, dissociation, and charge transport, the nanoscale morphology ensures nanometer phase separation between donor and acceptor components in the active layer. It was demonstrated that because of the exciton’s short lifetime, only small diffusion distances (10–20 nm) are needed for all photo-generated excitons to reach the interfacial region where they can separate into free charge carriers. There is a comprehensive explanation of the architecture of organic solar cells using single layer, bilayer, and bulk heterojunction (BHJ) devices. The short circuit current density (Jsc), open circuit voltage (Voc), and fill factor (FF) all have a significant impact on the performance of organic solar cells (OSCs). Since the BHJ concept was first proposed, significant advancement and quick configuration development of these devices have been accomplished. Due to their ability to combine great optical and electronic properties with strong thermal and chemical stability, conjugated polymers are unique semiconducting materials that are used in a wide range of applications. According to the fundamental operating theories of OSCs, unlike inorganic semiconductors such as silicon solar cells, organic photovoltaic devices are unable to produce free carrier charges (holes and electrons). To overcome the Coulombic attraction and separate the excitons into free charges in the interfacial region, organic semiconductors require an additional thermodynamic driving force. From the molecular engineering of conjugated polymers, it was discovered that the most crucial obstacles to achieving the most desirable properties are the design and synthesis of conjugated polymers toward optimal p-type materials. Along with plastic solar cells (PSCs), these materials have extended to a number of different applications such as light-emitting diodes (LEDs) and field-effect transistors (FETs). Additionally, the topics of fluorene and carbazole as donor units in conjugated polymers are covered. The Stille, Suzuki, and Sonogashira coupling reactions widely used to synthesize alternating D–A copolymers are also presented. Moreover, conjugated polymers based on anthracene that can be used in solar cells are covered

Synthesis and characterization of polymers containing ethynylene and ethynylene-thiophene based alternating polymers containing 2,1,3-linked naphthothiadiazole units as acceptor linked with fluorine as donor: electrochemical and spectroscopic studies

The effect of ethynylene or ethynylene–thiophene spacers on the band gap of alternating polymers, containing 4,9-naphthothiadiazole units as an acceptor and 2,7-linked fluorene repeat units as a donor, were investigated. The Sonogashira coupling reaction was employed to prepare the two novel copolymers, namely ((9,9-dioctyl-fluorene)-2,7-diethynylene-alt-4,9-2,1,3-naphthothiadiazole (PFDENT) and poly(5,5’-(9,9-dioctyl-fluorene-2,7-diyl)bis(ethynyl-2-thienyl)-alt-4,9-(2,1,3-naphthothiadiazole) (PFDTENT). The optical, electrochemical and thermal properties of the two obtained polymers were widely investigated and compared. Both resulting polymers showed low solubility in common organic solvents and moderate molecular weights. It is believed that the introduction of acetylene linkers rather than acetylene–thiophene spacers on the polymer chains reduces the steric hindrance between the donor and acceptor units which leads to the adoption of more planar structures of polymeric chains, resulting in decreased molecular weights of the resulting conjugated polymers. Thus, both ethynylene-based polymers and ethynylene–thiophene-based polymers showed red-shifted absorption maxima compared to their counterpart (thiophene-based polymer), owing to the adoption of more planar structures. Optical studies revealed that the new ethynylene and ethynylene–thiophene-based polymers displayed low band gaps compared to their thiophene analogue polymer PFDTNT. Both resulting polymers showed good thermal stability. X-ray diffraction (XRD) patterns of both polymers revealed that PFDENT and PFDTENT possessed an amorphous nature in solid state

Partial dietary fish meal replacement with cotton seed meal and supplementation with exogenous protease alters growth, feed performance, hematological indices and associated gene expression markers (GH, IGF-I) for Nile tilapia, Oreochromis niloticus

A 12-week feeding trial was conducted to evaluate the effect of different ratios of fish meal (FM): cotton seed meal (CSM) without or with inclusion of exogenous protease in diets on growth performance, hematology, digestibility and selected gene expression markers (GH and I (IGF-I) of juvenile Nile tilapia. The experimental diets were categorized into three groups; the first group CSM1 which contained fish meal protein: cotton seed meal protein (FM: CSM = 2:1), the second group CSM2 which contained FM: CSM = 1:1 and the third one CSM3 contained FM: CSM = 1:2 on protein content based. All groups were supplemented with exogenous protease at 0 and 2500 U kg−1 diet, respectively. All diets were fed to fish (initial body weight 11.62 ± 0.03 g fish−1) in triplicate aquaria twice daily. The higher weight gain (WG), protein efficiency ratio (PER) and best feed conversion ratio (FCR) were recorded by fish fed CSM1 and CSM2 and supplemented with 2500 U protease/kg diet. The highest apparent digestibility coefficient of crude protein, crude lipid and digestible energy, and apparent availability coefficient of essential amino acids were obtained by fish receiving CSM1 and CSM2 supplemented with protease (2500 U protease kg−1 diet). The highest mean values of Hb, Htc and RBCs were recorded in fish fed CSM1 and CSM2 supplemented with protease enzyme (2500 U protease kg−1 diet). Serum of alanine and aspartate aminotransferase activities were improved due to dietary protease (2500 U protease kg−1 diet) supplementation, also, fish received the diets supplemented with protease 2500 U kg−1 diet generally had higher total protein, albumin, calcium and phosphorus than those fed diets without supplement. The highest growth hormone (GH) gene expression in brain and liver of tilapia were obtained in the group fed CSM3 and un-supplemented with protease enzyme followed by CSM2 (un-supplemented). On the other hand, tilapia fed CSM1 and CSM2 supplemented with protease enzyme showed the highest values of gene expression of insulin like growth factor I (IGF-I) in brain and liver of tilapia compared to other groups. Results above showed that supplementation of protease can improve growth, nutrient assimilation, and hematology and alter gene expression of GH and IGF-I of Nile tilapia