Microsurgical treatment of intramedullary spinal cord tumors

Eighty patients with intramedullary spinal cord tumors were treated by microsurgical methods between 1988 and 1996. Twenty-nine patients were diagnosed with astrocytoma, 36 with ependymoma, five with metastasis, four with lipoma, three with dermoid or epidermoid tumor, two with neurofibroma, and one with neuroma. Vascular and infectious lesions (such as abscesses and hemangioblastomas) were excluded. After laminectomy, total removal of the lesion was achieved in 68 of 80 patients and subtotal removal in 12. Postoperative radiation therapy was performed in 13 of 80 patients. The follow-up period ranged from 12 to 92 months (mean 42.2 months). All patients underwent preoperative and postoperative magnetic resonance imaging at intervals ranging from 3 months to 5 years postoperatively. Four patients showed clinical and radiological evidence of local tumor recurrence during the follow-up period. Four patients died 5 months to 15 months postoperatively from the re-expansion of their primary metastatic disease. The operative results at long term (after the 6th postoperative month) were better than the results at short term (before the 6th postoperative month) and revealed clinical improvement in 63, no change in 10, and deterioration in seven patients. We recommend early radical surgery, whenever possible, to be performed when the patient's neurological status is still good. Subtotal removal and irradiation are better for malignant or metastatic tumors. Partial decompressive removal is best for large intramedullary lipomas. Plastic laminotomy with preservation of the intervertebral joints is especially recommended in young or middle-aged patients.     

Typical and atypical fractures of the odontoid process in young children. Report of two cases and a review of the literature

The most common injury to the odontoid process in children under the age of seven years is a fracture through the synchondrosis with or without anterior displacement of the odontoid process, but this is not the only type of fracture of the odontoid process in this age-group. Fractures above and below the synchondrosis and fractures with posterior displacement were described. Typical clinical features of these fractures are: (1) major and blunt trauma, (2) neck pain and resistance to active and passive head movements; and (3) no or only slight neurological deficits. Conservative treatment had excellent results in the majority of cases. Nevertheless, there are a few specific indications for surgery.     

Tick infestation patterns and prevalence of Borrelia burgdorferi in ticks collected at a veterinary clinic in Germany

A total of 4803 domestic and wild animals which were presented for examination at a veterinary clinic in north Baden, Germany over a period of 1 year were examined for tick infestation. A total of 434 nymphal and adult ticks were collected from 175 hosts. Ticks found belonged to the species Ixodes ricinus (385), Ixodes hexagonus (48), and Ixodes ventalloi (one). The polymerase chain reaction was used to examine 132 I. ricinus and 21 I. hexagonus for the presence of Borrelia burgdorferi. Twenty-two per cent of adult I. ricinus were infected as were one female and one larval I. hexagonus.     

Steigerung der Softwareflexibilität bei Geschäftsprozessänderungen

In times of continuous change, companies need to adjust their business processes to gain sustainable competitive advantage. Resulting changes in the company’s IT currently require the involvement of developers from departments that are mostly not aligned with the business. These changes often result in high transaction and labor costs. The article presents a platform-based method to adjust business processes with the aim of increasing both efficiency and flexibility compared to current approaches. The core of our work is an evaluation against traditional component-based software development using a sound simulation model. Three real-world scenarios of business process change show that – despite a slight increase in transaction costs – our suggested method decreases labor costs while increasing operational flexibility.     

A homogeneous heating technique in preform manufacturing

A new heating technique in preform manufacturing, which enables a faster collapse and a larger preform size, has been developed. On an ordinary MCVD preform station, the torch has been replaced by a microwave (dielectric) heater. With this equipment both deposition and collapse of thick-walled tubes have been performed. Preforms, of single-mode design and with an outer diameter of 35 mm, have been fabricated. This preform size corresponds to 40 km of fiber per half meter preform.     

Response of phytoplankton from the metalimnetic chlorophyll maximum to macro- and micro-nutrients amendments in Lake Geneva

Despite re-oligotrophication and low trace elements concentrations, direct determination of limiting nutrient(s) of the phytoplankton community in Lake Geneva is still missing. Incubation experiments were carried out with either addition of phosphate (+P), nitrate (+N), reactive silica (+Si), iron (+Fe), nickel (+Ni) and molybdenum (+Mo) to surface water collected between 9 and 12?m, during seasonal fieldtrips in 2015. Macro- and micro-nutrients, dissolved concentrations, temperature and irradiance as well as chlorophyll a (Chl a) levels, Chl a:POC ratios, POP:POC ratios and Chl a variable fluorescence parameters were quantified. The rapid phosphorus consumption, elevated inorganic nitrogen to phosphorus ratios and increased Chl a, Chl a:POC and POP:POC, in response to P additions, all indicated a phosphorus limitation in phytoplankton. Moreover, none of the measured parameters differed significantly from the control in the other treatments. These results were also confirmed by the response of Chl a variable fluorescence. The effective photosystem II quantum yield in ambient light, the absolute electron transfer rate and the connectivity, under 53?μmol photons/m²/s illumination, significantly increased while the non-photochemical quenching decreased in the +P treatment. Phytoplankton cells supplemented with phosphate were thus more efficient to capture photons and to drive them into photochemistry at light levels close to in situ levels. This is the first study to demonstrate directly a phosphorus limitation in Lake Geneva, pointing towards the success of its re-oligotrophication process.