Growth Performance of Male NZW Rabbits Fed Diets Supplemented with Beneficial Bacteria or Live Yeast

 Sixty male growing NZW rabbits aged eight weeks old, weighed in average 837.0±50.0g were randomly ranked in four equal groups to feed on four experimental diets for 10 weeks. All groups were fed a uniform rabbits pelleted diet, where R1 diet was without supplement ( control ), R2 supplemented with 0.1% Bacillus subtilis , R3 with 0.1% live Saccharomyces cerevisiae and R4 with 0.05% Bacillus s. + 0.05% Sacchromyces c. mixture. The results indicated that the voluntary feed intake did not influenced by bacteria or yeast supplementations, meanwhile body  weight gain and feed  efficiency  were obviously improved ( P < 0.05 )  with  diets supplemented with yeast, bacteria or their mixture than control. Nutrients digestion coefficients and dietary nitrogen utilization were (P< 0.05) higher with yeast or bacteria supplemented diets than those of R1 and R4. The lower values concerning weight gain, nutrients digestibility and dietary nitrogen utilization with feeding Yeast + bacteria mixture (R4) than other supplemented diets, reveals that there was an antagonistic effect between the two microbial types on feed utilization of rabbits. Carcass characteristics, dressing % calculated relative to pre-slaughter or empty body weight, meat: bone ratio and body chemical composition were not statistically different among groups

Carbon nanotubes-cellulose acetate nanocomposites: membranes for water desalination

Cellulose acetate (CA) (Mw = 52,000 Da) membranes were prepared by phase inversion (PI) using acetone as a solvent. Investigation of different preparation conditions were carried out. The effect of membrane casting thickness, CA content, coagulation bath temperature (PI temperature), solvent evaporation, addition of a non-solvent (deionized water), and addition of multi-walled carbon nanotubes (MWCNTs) on membrane morphology and performance (permeation rates and salt rejection rates) were investigated. Membranes morphologies were studied using scanning electron microscopy (SEM). Membranes permeations rates and salt rejection rates were investigated using 1000 ppm NaCl solution. Optimum conditions for developing a CA based nanocomposites were attained, entailing 15 wt% CA content, 20 wt% H2O non-solvent additive, low functionalized CNTs contents (0.0005, 0.005, and 0.01 wt%), PI at room temperature, and sonication time for CNTs proper dispersion less than 1 minute. MWCNTs/CA nanocomposites membranes were prepared. MWCNTs were first functionalized by oxidation purification in a strong acidic medium to enhance their dispersion within the polymer matrix, and the success of the functionalization of MWCNTs was characterized using Fourier transform infrared (FTIR) spectroscopy. The nanocomposites morphologies were characterized by several methods by SEM and nitrogen adsorption. SEM images showed large networks of MWCNTs, randomly oriented and properly dispersed, with a significant decrease in the number of macrovoids development with CNT content increase at the same final thickness of the nanocomposites. This was verified by analysis of pore sizes (differential volumes and surface areas), which were found to decrease with the increase in CNT content. Nanocomposites permeations rates and salt rejection rates were investigated using 1000 ppm NaCl solution, and it was found that permeation improved significantly with the addition of CNTs, with the improvement being highest for lowest CNT content. Salt rejection was found to decrease with the presence of CNTs. However the decrease was minimal for low CNT contents. In this respect, it was possible to prepare CA-CNT nanocomposite membranes with improved permeation of 19.57 L/m2h, together with a minimal decrease of salt retention performance of 69.4% at 24 bars operating pressure. The membranes performance could be explained by membrane morphology (surface areas and porosity)

Effect of dietary moringa (Moringa oleifera) and rosemary (Rosmarinus officinalis) leaves or their mixture on productive performance, carcass characteristics and antioxidant enzymes of rabbits reared under heat stress conditions

Sixty growing New Zealand White (NZW) male rabbits aged six weeks, weighed 750.0±5g were used in a feeding experiment lasted 9 weeks. Rabbits were housed in controlled-climatic conditions at a mean ambient temperature 33.1°C and relative humidity 43% to keep rabbits under heat stress conditions. The rabbits were randomly distributed to four equal groups (five replicates each). The 1st group fed the control diet (R1), R2 group fed diet supplemented with 1% moringa leaves, R3 group fed diet supplemented with 1% rosemary leaves, while R4 group fed diet supplemented with a mixture of moringa and rosemary leaves of 0.5% each. Diets and water were provided ad-libitum over nine weeks. The results revealed that live body weight, average daily gain and feed conversion ratio were significantly improved with R4 and R2 diets, while daily feed intake was not affected among groups. Apparent digestibility of crude fiber and ether extract were increased (p≤0.05) with R2 diet. Nitrogen balance was positive for all groups, however improvement (p≤0.05) was detected with R2 than control. Carcass characteristics were not affected among experimental groups. Hemo-lysatic catalase, glutathione peroxidase and super-oxide dismutase levels were increased (p≤0.01) with supplemented diets, while malondialdehyde was obviously decreased in the experimental groups compared with the control. It could be concluded that, supplementing diets with 1% moringa dry leaves or mixture of moringa leaves and rosemary leaves by 0.5+0.5% can be used to improve growth performance, nutrient digestibility and antioxidant status of rabbits reared under heat stress conditions

Evaluating System Performance in Gigabit Networks

With the current wide deployment of Gigabit Ethernet technology in the backbone and workgroup switches, the network performance bottleneck has shifted for the first time in nearly a decade from the network to the end hosts and servers. This dramatic bandwidth increase calls for optimizations and good design considerations in many key components of the hosts and servers. These key components include network adaptor, operating system, protocol stack, memory, and processing power. More importantly the high bandwidth increase can negatively impact the OS performance due to the interrupt overhead caused by the incoming gigabit traffic. This paper presents models and analytical techniques for studying such a negative impact. We first present an analytical model for the ideal system when interrupt overhead is ignored. We then present two models which describe the impact of high interrupt rate on system throughput. One model is for network adaptors not equipped with DMA engines, and the other model is for network adaptors equipped with DMA engines. In addition we study the system performance when using different system delivery options of packet data to user applications. Results from both simulations and reported experimental findings show that our analytical models are valid and give a good approximation

Tolerance of benthic foraminifera to anthropogenic stressors from three sites of the Egyptian coasts

AbstractSurely the coupling of natural and anthropogenic stressors combined with a lack of regulation resulted in the current threat to a large part of coastal marine biodiversity as well as coastal human societies, particularly in highly populated regions. The distribution pattern of benthic foraminifera as sensitive bio-indicator is utilized to assess human-induced impact on the coastal area, at Alexandria, Port Said and Suez cites of Egypt. Twenty-two benthic foraminiferal genera were identified and complied by principal component analysis into four factors through cluster analysis. Cross correlation of the generic composition, distribution and relative abundance of common genera in the three investigated cores revealed three different coastal environments entities. The categorized environment ranged from light human impact as Alexandria site to heavily impacted by human activities as Port Said and Suez sites. Fauna of Alexandria site reflects an increase in un-polluted water activity revealing high-energy erosive environment. The second entity involves Port Said site, which represents a highly stressed coastal environment, corresponding to high-energy transport conditions influenced by fresh water flush from local Manzala Lake via Bougaz El Gamel outlet while Suez site is influenced by marine hypersaline water coupling with intensified levels of industrial and domestic pollution, attributed to the anthropogenic impact

"So the World Will Know Our Story": Ethical Reflections on Research with Families Displaced by War

In this article we examine the ethical implications of a qualitative research study exploring the everyday mobilities of Syrian families displaced in Lebanon. The multiple methods of data collection - collaborative family interviews, children's drawing and mapmaking, GIS-tracked neighborhood walks, and activity logging - encouraged children and family voices. At the same time, these methods provide an opportunity to explore family networks, relationships, and environments that are impacting their lives in the context of war and displacement. These methods, like all research with vulnerable populations, also raise several ethical questions. Using a process of ethical reflexivity, we discuss six ethical points related to both procedural and micro-ethics. In addition to shedding light on the importance of uncovering the everyday experiences of refugees using creative methods, we suggest broader ethical implications regarding how we respectfully work with vulnerable populations while still upholding research integrity.In diesem Beitrag befassen wir uns mit den ethischen Implikationen einer qualitativen Studie zu Mobilität im Alltag von syrischen Familien, die angesichts des Krieges in Syrien in den Libanon geflohen sind. Die Daten wurden mit verschiedenen Methoden erhoben - mit kollaborativen Familieninterviews, Zeichnungen und Karten von Kindern, GIS-unterstützten Spaziergängen sowie einem Logbuch für Aktivitäten - wodurch insbesondere die Teilnahme von Kindern und Familien ermöglicht wurde. Diese Methoden erlaubten es, familiäre Netzwerke und Beziehungen zu untersuchen und auch die Umwelten zu erfassen, die auf das Leben der Familien nach Krieg und Flucht einwirken. Unser Vorgehen, wie im Grunde jede Erforschung von vulnerablen Gruppen, war von ethischen Fragen begleitet. Auf Basis eines ethischen Reflexionsprozesses diskutieren wir in diesem Beitrag sechs Punkte, die sowohl mit Fragen der prozeduralen Ethik als auch mit Fragen der Mikro-Ethik verbunden sind. Dabei unterstreichen wir die Bedeutung von kreativen Forschungsmethoden, die es erlauben, alltägliche Erfahrungen von geflüchteten Familien zu erfassen. Darüber hinaus besprechen wir weiter gefasste ethische Implikationen, insbesondere wie sich eine respektvolle Arbeit mit vulnerablen Bevölkerungsgruppen mit einer Gewährleistung der Integrität als Forschende verbinden lässt

Evaluating system performance in Gigabit networks

With the current wide deployment of Gigabit Ethernet technology in the backbone and workgroup switches, the network performance bottleneck has shifted for the first time in nearly a decade from the network to the end hosts and servers. This dramatic bandwidth increase calls for optimizations and good design considerations in many key components of the hosts and servers. These key components include network adaptor, operating system, protocol stack, memory, and processing power. More importantly the high bandwidth increase can negatively impact the OS performance due to the interrupt overhead caused by the incoming Gigabit traffic. This paper presents models and analytical techniques for studying such a negative impact. We first present an analytical model for the ideal system when interrupt overhead is ignored. We then present two models which describe the impact of high interrupt rate on system throughput. One model is for network adaptors not equipped with DMA engines, and the other model is for network adaptors equipped with DMA engines. In addition we study the system performance when using different system delivery options of packet data to user applications. Results from both simulations and reported experimental findings show that our analytical models are valid and give a good approximation