Towards QoS-aware Provisioning of Chained Virtual Security Services in Edge Networks

Future networks are expected to deliver low-latency, user-specific services in a flexible and efficient manner. Operators have to ensure infrastructure resilience in the face of such challenges, while maintaining service guarantees for subscribed users. One approach to support emerging use cases is through the introduction and user of virtualised network functions (VNFs) at the edge of the network. While placement of VNFs at the network edge has been previously studied, it has not taken into account services comprised of multiple VNFs and considerations for network security. In this paper we propose a mathematical model for latencyoptimal on-path allocation of VNF chains on physical servers within an edge network infrastructure, with special considerations for network security applications and operator’s best practices. We acknowledge the challenges of employing optimal solutions in real networks and provide the Minimal Path Deviation Allocation algorithm for placement of security-focused network services in a distributed edge environment, minimising end-to-end latency for users. We then evaluate our placement results over a simulated nation-wide network using real-world latency characteristics. We show that our placement algorithm provides near-optimal placement, with minimal latency violations with respect an optimal solution, whilst offering robust tolerance to temporal latency variations

Application of direct bioautography and SPME-GC-MS for the study of antibacterial chamomile ingredients

The isolation and characterization of antibacterial chamomile components were performed by the use of direct bioautography and solid phase microextraction (SPME)-GC-MS. Four ingredients, active against Vibrio fischeri, were identified as the polyacetylene geometric isomers cis- and trans-spiroethers, the coumarin related herniarin, and the sesquiterpene alcohol (-)-alpha-bisabolol

A rare case of severe craniocerebral trauma with penetrating head injury

Penetrating head injury remains an important issue even in modern neurosurgery. Less frequent than other neurosurgical diseases, they may still pose some management problems. The authors present one extremely rare case of suicide attempt by penetrating head injury with harpoon at a male middle aged patient associated with iatrogenous pneumothorax. Operated with a simple occipital craniectomy, the patient had a pretty good recovery with minimal neurological deficit (facial paresis)

The laparoscopic treatment of perforated duodenal ulcer in Romania – a multicentric study

Clinica Chirurgie 2, Timișoara, România, Clinica Chirurgie, Spitalul de Urgență, București, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Aims. This retrospective study was evaluated the results of laparoscopic treatment of the perforated duodenal ulcer (PDU) in 6 Romanian centres with an important experience in laparoscopic surgery.Methods. Between 2000 and 2010, 221 patients (38 females and 183 men) aged from 18 to 78 years, were operated laparoscopicaly for PDU, by using 3 (66.0%), 4 (27%) or 5 (7.0%) trocars. Forty six (20.8%) of them had a weak, 143(64.7%) an important and 32(14.5%) a grave peritonitis. Procedures performed were: simple suture 84(38.1%) patients, suture with epiplonoplasty 135(61.1%) patients, only epiplonoplasty 1(0.4%) patients, excision with suture 1(0.4%) patients. All patients had abundant peritoneal cavity washing and tub drainage (1-3 tubs).Results. The interventions lasted between 30 and 120 min, with an average of 63 min. No mortality was reported. Postoperative oral nutrition began after 24 hours for 114(51.6%) patients and after intestinal transit has restarted for 107(48.4%) patients. The intestinal transit has restarted after 1-6 days (average 3.5 days), depending of the gravity of peritonitis. Complications were: parietal infections 3 (1.3%), duodenal fistula 1 (0.4%), abdominal abcesses 1(0.4%), digestive haemorrhage 1(0.4%) and duodenal stenosis 1 (0.4%). Hospitalization lasted between 2 and 13 days (average 5.5 days). In comparison with open techniques, patients had the same intravenous perfusions, less pain, less antibiotics, less dressings, less complications during postoperative evolution. Conclusion. Laparoscopic treatment of PDU is safe even in case of severe peritonitis, with faster patient’s recovery. with less complications and with less postoperative medical care than open procedures. Aims. This retrospective study was evaluated the results of laparoscopic treatment of the perforated duodenal ulcer (PDU) in 6 Romanian centres with an important experience in laparoscopic surgery.Methods. Between 2000 and 2010, 221 patients (38 females and 183 men) aged from 18 to 78 years, were operated laparoscopicaly for PDU, by using 3 (66.0%), 4 (27%) or 5 (7.0%) trocars. Forty six (20.8%) of them had a weak, 143(64.7%) an important and 32(14.5%) a grave peritonitis. Procedures performed were: simple suture 84(38.1%) patients, suture with epiplonoplasty 135(61.1%) patients, only epiplonoplasty 1(0.4%) patients, excision with suture 1(0.4%) patients. All patients had abundant peritoneal cavity washing and tub drainage (1-3 tubs). Results. The interventions lasted between 30 and 120 min, with an average of 63 min. No mortality was reported. Postoperative oral nutrition began after 24 hours for 114(51.6%) patients and after intestinal transit has restarted for 107(48.4%) patients. The intestinal transit has restarted after 1-6 days (average 3.5 days), depending of the gravity of peritonitis. Complications were: parietal infections 3 (1.3%), duodenal fistula 1 (0.4%), abdominal abcesses 1(0.4%), digestive haemorrhage 1(0.4%) and duodenal stenosis 1 (0.4%). Hospitalization lasted between 2 and 13 days (average 5.5 days). In comparison with open techniques, patients had the same intravenous perfusions, less pain, less antibiotics, less dressings, less complications during postoperative evolution. Conclusion. Laparoscopic treatment of PDU is safe even in case of severe peritonitis, with faster patient’s recovery. with less complications and with less postoperative medical care than open procedures

Low-loss, low-confinement GaAs-AlGaAs DQW laser diode with optical trap layer for high-power operation

A low-confinement asymmetric GaAs-AlGaAs double-quantum-well molecular-beam-epitaxy grown laser diode structure with optical trap layer is characterized, The value of the internal absorption coefficient is as low as 1.4 cm-1, while keeping the series resistance at values comparable cm with symmetrical quantum-well gradient index structures in the same material system. Uncoated devices show COD values of 35 mW/µm. If coated, this should scale to about 90 mW/µm. The threshold current density is about 1000 A/cm2 for 2-mm-long devices and a considerable part of it is probably due to recombination in the optical trap layer. Fundamental mode operation is limited to 120-180 mW for 6.5-µm-wide ridge waveguide uncoated devices and to 200-300 mW for 13.5-µm-wide ones, because of thermal waveguiding effects. These values are measured under pulsed conditions, 10 µs/l m

PROPOSALS FOR IMPROVING THE PROCESS OF SEED DISTRIBUTION

The paper presents theoretical studies performed to adapt a universal drills forsowing of seeds for different sizes by improving their distribution process, changing the distributor groove