Low absorption InP/InGaAs-MQW phase shifters for optical switching

InP/InGaAs-MQW phase shifters with low absorption loss and low electroabsorption loss have been realized. Phase shift efficiency for TE-polarized light at lambda =1.55 mu m was 6.8 degrees V/sup -1/ mm/sup -1/ with negligible absorption loss and at lambda =1.51 mu m the efficiency was 8.9 degrees V/sup -1/ mm/sup -1/ with 5 dB/cm absorption los

Can interaction specificity in the fungus-farming termite symbiosis be explained by nutritional requirements of the fungal crop?

<p>Fungus-growing termites are associated with genus-specific fungal symbionts, which they acquire via horizontal transmission. Selection of specific symbionts may be explained by the provisioning of specific, optimal cultivar growth substrates by termite farmers. We tested whether differences in in vitro performance of Termitomyces cultivars from nests of three termite species on various substrates are correlated with the interaction specificity of their hosts. We performed single-factor growth assays (varying carbon sources), and a two-factor geometric framework experiment (simultaneously varying carbohydrate and protein availability). Although we did not find qualitative differences between Termitomyces strains in carbon-source use, there were quantitative differences, which we analysed using principal component analysis. This showed that growth of Termitomyces on different carbon sources was correlated with termite host genus, rather than host species, while growth on different ratios and concentrations of protein and carbohydrate was correlated with termite host species. Our findings corroborate the interaction specificity between fungus-growing termites and Termitomyces cultivars and indicate that specificity between termite hosts and fungi is reflected both nutritionally and physiologically. However, it remains to be demonstrated whether those differences contribute to selection of specific fungal cultivars by termites at the onset of colony foundation.</p

Loss of HR6B ubiquitin-conjugating activity results in damaged synaptonemal complex structure and increased crossing-over frequency during the male meiotic prophase.

The ubiquitin-conjugating enzymes HR6A and HR6B are the two mammalian homologs of Saccharomyces cerevisiae RAD6. In yeast, RAD6 plays an important role in postreplication DNA repair and in sporulation. HR6B knockout mice are viable, but spermatogenesis is markedly affected during postmeiotic steps, leading to male infertility. In the present study, increased apoptosis of HR6B knockout primary spermatocytes was detected during the first wave of spermatogenesis, indicating that HR6B performs a primary role during the meiotic prophase. Detailed analysis of HR6B knockout pachytene nuclei showed major changes in the synaptonemal complexes. These complexes were found to be longer. In addition, we often found depletion of synaptonemal complex proteins from near telomeric regions in the HR6B knockout pachytene nuclei. Finally, we detected an increased number of foci containing the mismatc

A Fibreoptic Endoscopic Study of Upper Gastrointestinal Bleeding at Bugando Medical Centre in Northwestern Tanzania: a Retrospective Review of 240 Cases.

Upper gastrointestinal (GI) bleeding is recognized as a common and potentially life-threatening abdominal emergency that needs a prompt assessment and aggressive emergency treatment. A retrospective study was undertaken at Bugando Medical Centre in northwestern Tanzania between March 2010 and September 2011 to describe our own experiences with fibreoptic upper GI endoscopy in the management of patients with upper gastrointestinal bleeding in our setting and compare our results with those from other centers in the world. A total of 240 patients representing 18.7% of all patients (i.e. 1292) who had fibreoptic upper GI endoscopy during the study period were studied. Males outnumbered female by a ratio of 2.1:1. Their median age was 37 years and most of patients (60.0%) were aged 40 years and below. The vast majority of the patients (80.4%) presented with haematemesis alone followed by malaena alone in 9.2% of cases. The use of non-steroidal anti-inflammatory drugs, alcohol and smoking prior to the onset of bleeding was recorded in 7.9%, 51.7% and 38.3% of cases respectively. Previous history of peptic ulcer disease was reported in 22(9.2%) patients. Nine (3.8%) patients were HIV positive. The source of bleeding was accurately identified in 97.7% of patients. Diagnostic accuracy was greater within the first 24 h of the bleeding onset, and in the presence of haematemesis. Oesophageal varices were the most frequent cause of upper GI bleeding (51.3%) followed by peptic ulcers in 25.0% of cases. The majority of patients (60.8%) were treated conservatively. Endoscopic and surgical treatments were performed in 30.8% and 5.8% of cases respectively. 140 (58.3%) patients received blood transfusion. The median length of hospitalization was 8 days and it was significantly longer in patients who underwent surgical treatment and those with higher Rockall scores (P < 0.001). Rebleeding was reported in 3.3% of the patients. The overall mortality rate of 11.7% was significantly higher in patients with variceal bleeding, shock, hepatic decompensation, HIV infection, comorbidities, malignancy, age > 60 years and in patients with higher Rockall scores and those who underwent surgery (P < 0.001). Oesophageal varices are the commonest cause of upper gastrointestinal bleeding in our environment and it is associated with high morbidity and mortality. The diagnostic accuracy of fibreoptic endoscopy was related to the time interval between the onset of bleeding and endoscopy. Therefore, it is recommended that early endoscopy should be performed within 24 h of the onset of bleeding

Haalbaarheid van een poliklinisch geriatrisch Revalidatieprogramma – lessen uit een pilotproject

Doel Beschrijven van de haalbaarheid van een poliklinisch geriatrisch behandelprogramma, als pilotproject ontwikkeld in Vivium Naarderheem. Methoden De uitkomsten werden onderzocht in een pretest-posttest design met één groep. Haalbaarheid werd onderzocht door mondelinge afname van een patiënttevredenheidsvragenlijst en door gestructureerde interviews met behandelaars en management. Het effect werd onderzocht door bij start (T0) en bij ontslag (T1) van het behandelprogramma schriftelijke vragenlijsten af te nemen: bij de patiënten over het participatieniveau en de gezondheidsgerelateerde kwaliteit van leven en bij hun mantelzorgers over de ervaren belasting. Resultaten Er werden 18 patiënten geïncludeerd. Vijftien daarvan revalideerden na een CVA. Behandelaars en managers vonden het programma uitvoerbaar, op voorwaarde dat het vervoer van de patiënten, de roosterplanning en de financiering goed geregeld zijn. Het behandelprogramma werd door de patiënten met een gemiddeld rapportcijfer van 8,1 gewaardeerd. Er zijn geen statistisch significante verschillen gevonden in het participatieniveau van de patiënten en in de zorgbelasting van de mantelzorgers bij de start en het einde van de poliklinische behandeling. De algemene gezondheidsbeleving, gemeten met de RAND-36, was na poliklinische revalidatie achteruit gegaan. Conclusie Uit deze pilotstudie blijkt dat vijftien van de achttien patiënten die gebruik maken van de polikliniek, revalideert vanwege CVA. Poliklinische geriatrische revalidatie is een door de bevraagde patiënten gewaardeerde aanvulling op de klinische revalidatieperiode, en de uitvoering ervan lijkt haalbaar. Een verbetering van de gezondheidstoestand of van het participatieniveau kon niet worden aangetoond