The Timing of Egg-laying in Macrobiotid Species (Tardigrada) on the Island of Newfoundland

Previous sampling of lichens and mosses on the island of Newfoundland has not located any macrobiotid (family Macrobiotidae) eggs, which are often crucial to the positive identification of adults of this family, particularly Macrobiotus and Minibiotus species. Because recent studies have established that egg-laying in macrobiotid species in the more northerly Labrador part of the province occurs in late summer and early fall, it was hypothesized that egg-laying on the more southerly island of Newfoundland would take place later in the year. In this study, conducted on the Burin Peninsula from September to December 2005, moss samples were taken every 2 weeks and macrobiotid adults and eggs were extracted. The eggs of 3 species of Macrobiotus and 1 species of Minibiotus were recovered later in the fall after the first frost

Cooling of a vial in a snapfreezing device without using sacrificial cryogens

A fresh and frozen high-quality patient bio-sample is required in molecular medicine for the identification of disease-associated mechanism at molecular levels. A common cooling procedure is immersing the tissue enclosed in a vial in a coolant such as liquid nitrogen. This procedure is not user friendly and is laborious as reducing the lag time from excision time to freezing depends on the logistic organizational structure within a hospital. Moreover snapfreezing must be done as soon as possible after tissue excision to preserve the tissue quality for molecular tests. Herein, we report an electrically powered snap freezing device as an alternative to quenching the vial in liquid nitrogen and therefore can be used directly at the location where the tissue is acquired. This device also facilitates the study of the effect of freezing conditions on the various molecular processes in the samples. Cooling experiments of a vial in the snap freezing device show that the cooling rates similar to or faster than quenching in liquid nitrogen are feasible. We performed experiments with several set point conditions and compared the results with a mathematical model

Transverse crack initiation under combined thermal and mechanical loading of Fibre Metal Laminates and Glass Fibre Reinforced Polymers

The paper describes a temperature-dependent extension of the classical laminate theory (CLT) that may be used to predict the mechanical behaviour of Fibre Metal Laminates (FML) at cryogenic conditions, including crack initiation. FML are considered as a possible alternative class of structural materials for the transport and storage of liquified gasses such as LNG. Combining different constituents in a laminate opens up the possibility to enhance its functionality, e.g. offering lower specific weight and increased damage tolerance. To explore this possibility, a test programme is underway at the University of Twente to study transverse crack initiation in different material combinations under combined thermal and mechanical loading. Specifically, the samples are tested in a three-point bending experiment at temperatures ranging from 77 to 293 K. These tests will serve as a validation of the model presented in this paper which, by incorporating temperature-dependent mechanical properties and differential thermal expansion, will allow to select optimal material combinations and laminate layouts. By combining the temperature-dependent mechanical properties and the differential thermal contraction explicitly, the model allows for a more accurate estimate of the resulting thermal stresses which can then be compared to the strength of the constituent materials

Thermal and electrical design of superconducting demonstrator for magnetic density separation

In this paper the focus is on thermal and electrical design aspects of a NbTi-based demonstrator magnet for magnetic density separation (MDS) that is being constructed at the University of Twente. MDS is a recycling technology that allows the separation of non-magnetic particles based on their mass density, using a vertical magnetic field gradient and a ferrofluid. To minimize the distance between the planar array of racetrack coils and the ferrofluid bath, the system is conduction-cooled. First the thermal design is presented, which shows that the coils can operate below 4.5 K with sufficient margin using a single cryocooler. High-purity aluminium heat drains enable a low thermal gradient across the cold mass. The current path is introduced, as well as the adopted protection scheme. The magnet's stored energy can safely be dumped in the coils. Diodes are placed (anti-)parallel to the coils in the cold to prevent high terminal voltages. In the case of a quench in the superconducting part of the current leads or an external anomaly, a switch is opened and the current is forced through a resistor in series with the diodes, causing a deliberate transition of the coils to the normal state and thus a fast ramp-down

Is Intraoperative Remifentanil Associated With Acute or Chronic Postoperative Pain After Prolonged Surgery? An Update of the Literature

OBJECTIVE:: Remifentanil is an ultra-short-acting opioid that is used commonly during both short-term and prolonged surgery. This review investigated associations of intraoperative remifentanil administration with acute postoperative pain, hyperalgesia, and chronic postoperative pain, with emphasis on the perioperative coanesthetic drug regimen used. METHODS:: Medline and Embase databases were searched for randomized studies, evaluating the intraoperative use of remifentanil (>2▒h) versus another analgesic or a different dosage of remifentanil, and reporting acute postoperative pain parameters such as postoperative pain scores, hyperalgesia, acute opioid tolerance, or analgesics requirements. Furthermore, all studies in which remifentanil was used intraoperatively and parameters for chronic postoperative pain were measured were included (pain levels after a prolonged period of time after surgery). RESULTS:: From the 21 studies that were identified, less than half of the studies found higher acute postoperative pain and/or higher postoperative analgesic requirements after intraoperative remifentanil use. Coanesthetics to some extent determined this incidence, with mainly studies using volatile agents reporting increased pain levels. There was less evidence when remifentanil was combined with total intravenous anesthesia or a combination of anesthetics. The limited number of studies (n=4) evaluating chronic pain suggested a potential association with the intraoperative use of remifentanil. DISCUSSION:: Although studies are diverse and sample sizes small, coanesthetics used in combination with remifentanil may influence the occurrence of postoperative hyperalgesia. No firm conclusions could be made regarding acute and chronic pain, indicating that further research with the goal to investigate the effect of volatile or intravenous anesthetics along with simultaneous remifentanil infusion on acute and chronic postoperative pain is needed