Book review : What they Saw in America

برر الكاتب نقد القيم الثقافية لبلاده من خلال أناس أثبتوا ازدواجية في مشاعرهم تجاه أمريكا. واعتبر الكاتب أن الازدواجية من طبيعة الحياة والأشياء، وأن أجمل الأشياء تنطوي على ازدواجية. وإن التركيز على الأشياء السلبية لا يعني تفنيد الأشياء الجميلة، بل المقصود التعمق أكثر وتجديد الأفكار والتغلب على السلبيات. وإن هذا النوع من نقد قيم الثقافية الأمريكية مهم، ولاسيما حينما يأتي من غرباء أجانب، فإن فائدته للأمريكيين تكون أعظم ؛ ليفهموا أنفسهم. وكذلك سيساعدهم في اعتبار القيم الثقافية للآخر ووعيهم بأهمية الآخر المختلف. وستجعل هؤلاء الأمريكيين يعون جوهر الذهب ويتجاهلون المغشوش منه. وفي الختام برر تشسترتون بأن الأشياء الجميلة لا تُصدّر، بل يجب عليك أن تسافر إليها وذلك ردا على الناقدين الناقمين الذين يرون أن أمريكا صدرت أسوأ ما عندها من قيم إلى دول أخرى

Molecular identification of nontuberculous mycobacteria isolated from pyogenic bovine tissues in South Darfur State and Alsabalouga slaughterhouse at Omdurman area, Sudan

This study identified nontuberculous mycobacteria (NTM) recovered from bovine pyogenic affections obtained at necropsy using the molecular target 16S-23S rDNA internal transcribed spacer region. Postmortem inspection of cattle was conducted at South Darfur State abattoirs and Alsabalouga Slaughterhouse at Omdurman area during 2007-2009. Specimens were examined for the presence of acid fast bacteria (AFB) using microscopic and standard culturing techniques. AFB were identified phenotypically and confirmed by 16S-23S rDNA ITS. Fifty nine NTM were recovered and confirmed as acid fast filaments out of 165 positive AFB specimens, of which 52 isolates were identified as bovine farcy causative agents, while 7 cultures were excluded due to drying. 16S-23S rDNA ITS of NTM revealed three different amplicons 500 bp. (32) isolates, 550 bp. (2) isolates and 600 bp. (14) isolates. Four isolates were contaminated.Keywords: Acid fast bacteria, Bovine farcy, Nontuberculous mycobacteria, Pyogenic infectio

Evaluation of patellar height and measurement methods after valgus high tibial osteotomy

Several controversies exist regarding the surgical difficulties and the results of total knee arthroplasty performed after failed valgus high tibial osteotomy (HTO), and the main subject is the change in patellar height that results as patella baja or infera. The purpose of this retrospective study was to evaluate patellar height after valgus HTO and the measurement methods that were actually used. Eighty-five knees that were subjected to valgus HTO were evaluated both preoperatively and postoperatively according to the Insall-Salvati Index (ISI), Blackburne-Peel Index (BPI), and Caton Index (CI) to assess any alteration of patellar tendon height that was present. All cases underwent closing wedge osteotomy with three staples or plate internal fixation and were allowed early range of motion. Significant decrease in mean patellar height ratios was detected according to all three indexes at 85 months of mean follow-up. The percentages of the decrease were 8.26% in ISI, 9.08% in BPI, and 6.34% in CI. Two knees showed patella infera according to ISI, one according to BPI and three according to CI. There were no significant correlations between the indexes and clinical status of the patients. Elevation of patella relative to the femur in closing wedge valgus HTO procedure due to the shortening of the segment between tibial tuberosity and joint line is normally expected. A significant decrease in patellar height according to ISI suggests that there should be patellar tendon shortening as patellar height cannot be changed. BPI and CI for determining patellar height in valgus HTO do not accurately measure the alteration of patella because they may affect the tibial inclination and antero-posterior translation of the proximal fragment. Another measuring system based on femoral reference points should be proposed to determine the exact change of patellar height in the valgus HTO procedure

Manufacturing and characterization of in-situ alloyed Ti6Al4V(ELI)-3 at.% Cu by laser powder bed fusion

Biofunctionalization of Ti6Al4V alloy with metallic agents like Ag or Cu is a promising approach to add antibacterial properties and thus to reduce the risk of implant failure. This research investigates the in-situ alloying of Ti6Al4V(ELI) with 3 at.% Cu powders using Laser Powder Bed Fusion (L-PBF). The morphology and geometrical characteristics of the single tracks and layers were studied. Laser powers of 170 W and 340 W, and scanning speeds ranging from 0.4 to 1.4 m/s and 0.8-2.8 m/s were implemented. Single track results showed balling effect and humping at high scanning speeds, 1.4 m/s and 1.6 m/s, for each laser powder respectively. Conversely, keyhole formation occurred at lower scanning speeds of 0.4-0.6 m/s for 170 W laser power, and below and 0.8 m/s for 340 W laser power. For both laser powers, single layers resulted in smoother surfaces at lower scanning speeds. These results were used for the development of optimal process parameters for 3D cubes with 99.9 % density. Optimal process parameters were found for 170 W and 340W laser powders at 0.7-0.9 and 1.0-1.2 m/s scanning speeds, respectively. In-situ alloying by L-PBF was challenging and a homogeneous distribution of Cu within the alloy was hard to achieve. The increase in laser power from 170 to 340 W resulted in small increase in homogenization. Microstructural analyses after stress-relieving treatment showed the presence of alpha' and beta phases, as well as CuTi2 intermetallic precipitates. The finer microstructure together with CuTi2 intermetallic precipitates resulted in an increase in hardness. This study demonstrates the potential for printing in-situ alloyed Ti6Al4V(ELI)- 3 at.% Cu for biomedical applications. However, further studies are required to determine the effectiveness of antibacterial properties