Interstratal dewatering origin for polygonal patterns of sand-filled cracks: a case study from late Proterozoic metasediments of Islay, Scotland

Sand-filled cracks from the Lower Fine-grained Quartzite of Dalradian (late Proterozoic) age on the Island of Islay, western Scotland, may be divided into two main types, both of which form orthogonal and non-orthogonal closed patterns on bedding surfaces. Type 1 cracks are short and lenticular in cross-section, contain sand which had been injected downwards, and are found on the bottoms of cross-laminated sandstone beds. Type 2 cracks cut several beds and preserve evidence of upward flow of water-saturated sand. Both types of crack developed through the interstratal intrusion of water-saturated sand into shrinkage cracks in mud or muddy sand, not, as previously thought, as a result of sub-aerial desiccation, or sub-aqueous cracking of the sediment surface (synaeresis). These cracks likely resulted from layer-parallel contraction caused by compaction of mudstone layers during burial. Seismic shock may have provided the trigger for the preferential development of polygonal crack patterns in these layers instead of the more usual small-scale dewatering structures. From a detailed comparison with published descriptions of filled cracks from a number of different geological environments, it is concluded that interstratal cracking is a mechanism which rivals sub-aerial desiccation in importance, and is more common in the geological record than is currently realized

Increasing source to image distance for AP pelvis imaging – impact on radiation dose and image quality

Aim: A quantative primary study to determine whether increasing source to image distance (SID), with and without the use of automatic exposure control (AEC) for antero-posterior (AP) pelvis imaging, reduces dose whilst still producing an image of diagnostic quality. Methods: Using a computed radiography (CR) system, an anthropomorphic pelvic phantom was positioned for an AP examination using the table bucky. SID was initially set at 110 cm, with tube potential set at a constant 75 kVp, with two outer chambers selected and a fine focal spot of 0.6 mm. SID was then varied from 90 cm to 140 cm with two exposures made at each 5 cm interval, one using the AEC and another with a constant 16 mAs derived from the initial exposure. Effective dose (E) and entrance surface dose (ESD) were calculated for each acquisition. Seven experienced observers blindly graded image quality using a 5-point Likert scale and 2 Alternative Forced Choice software. Signal-to-Noise Ratio (SNR) was calculated for comparison. For each acquisition, femoral head diameter was also measured for magnification indication. Results: Results demonstrated that when increasing SID from 110 cm to 140 cm, both E and ESD reduced by 3.7% and 17.3% respectively when using AEC and 50.13% and 41.79% respectively, when the constant mAs was used. No significant statistical (T-test) difference (p ¼ 0.967) between image quality was detected when increasing SID, with an intra-observer correlation of 0.77 (95% confidence level). SNR reduced slightly for both AEC (38%) and no AEC (36%) with increasing SID. Conclusion: For CR, increasing SID significantly reduces both E and ESD for AP pelvis imaging without adversely affecting image quality

The biostratigraphy of the offshore Niger delta during the Late Quaternary: Complexities and progress of dating techniques

The Late Quaternary marine sediments from the Niger Delta lacks an age model using conventional radiocarbon dating due to the rarity of calcareous macrofossils. The proprietary nature of material drilled by companies prospecting for hydrocarbons in the Niger Delta basin, and in the rare cases when samples are available for study as well as freshwater dilution from continental runoff have contributed to this dearth of knowledge. The availability of three shallow marine (∼3 m) gravity cores obtained from the eastern, central, and western parts of the Niger Delta provides the opportunity for biostratigraphy utilising well-preserved marker species of planktonic foraminifera and calcareous nannofossils in the sediments. The last occurrence (LO) of planktonic foraminiferal species Globorotalia truncatulinoides (late Pleistocene) (MIS 2) and the first occurrence (FO) of Globorotalia tumida (Holocene) (MIS 1) are used to identify two interval zones in the gravity cores. The presence of the calcareous nannofossil Gephyrocapsa oceanica (all <3 μm in size) supports a late Pleistocene age (NN19 Zone) for the lower interval. In addition, an increase in the abundance of Emiliania huxleyi up-section is an indication of early Holocene age (NN20-NN21) for the upper interval

Interactive Video Gaming on the Intensive Care Unit: Design and feasibility study of an interactive video gaming device used for patients on the intensive care unit for rehabilitation purposes

Admission to the intensive care unit often has long lasting effects on patients’ further life. Not only can the reason for their admission leave several problems, but also mechanical ventilation, physical inactivity, sedation and delirium are only some of the factors that contribute to the problems left after ICU stay. Over 80,000 people are annually admitted to the intensive care units of the Dutch hospitals alone and, due to technical advancements, a rising number of patients survives critical illness. Post intensive care syndrome is the overarching name that combines all the physical and mental problems related to intensive care unit stay. It has been well established that rehabilitation and early mobilisation are effective counter measures against post intensive care syndrome. It has also been shown that interactive video gaming can play a useful role in rehabilitation as an addition to conventional therapy. Evidence has shown that the use of visual feedback improves performance and adherence to the therapy in comparison to regular of physical therapy. This design study is meant to create a new interactive video gaming device that allows ICU patients that are at least semi mobile and semi cooperative, to play video games with the aim to help them leave the ICU in the best physical and cognitive state as possible. To come up with the right design, a literature study on the relevant subjects has been done. Also, expert interviews with intensive care unit care-giving staff have been conducted and experience has been gained on the intensive care unit of the Erasmus medical center Rotterdam to make sure the design is done in the right context. Based on the outcomes of this research the decision was made to aim the design to help in activities of daily living. From this aim a specific goal was formulated: The goal is to create an interactive video game controlling system that allows ICU patients, that are at least semi mobile and semi cooperative, to play video games that simultaneously helps in increasing muscle strength, delivers distraction from the daily routine in the ICU and stimulates patients cognitively. Together with physiotherapists and intensivists from the Erasmus medical center Rotterdam a list of requirements for the final designs was created. As during activities of daily living hand grip is one of the most important aspects, the decision was made to use sub-maximal grip force control as the desired training form. Because of this two different versions of grip strength trainers were proposed. The first concept uses the medium wrap grasp as input movement and the second concept uses the power-sphere grasps. These are two of the most frequently used grasp types in daily life. The concepts are designed in a way that the force exerted on the device can be used to control a video game. Internal force sensing resistors, connected to an Arduino, translate the force to a useful signal to control the game. Ten prototypes were created to get to the final designs, which were then tested with patients on the ICU. As result of testing and iterating the concepts, two final designs were delivered, fulfilling the list of requirements. Feasibility tests of these designs were done on the ICU of the Erasmus medical center Rotterdam and were promising. ICU patients participating in the tests understood the game well, were capable of performing the required movements to play the game and delivered feedback on the design and the gaming experience. This paper has lead up to a final prototype that has gone through basic testing to check for feasibility and has proven to work. Further scientific research on a larger scale should be the next step to review the clinical effects of the device.Biomedical Engineerin

De kerk te Onderwierum

Prov. Groninger courant 5 mei 1840

Kerk te Sauwerdt

Prov. Groninger courant 5 mei 1840 Met inkt in hs.: Gesloopt in 1840

Werkgevers willen én kunnen werknemers met schulden meer hulp bieden

De hulp aan mensen met schulden is vooral een zaak van gemeenten, en in toenemende mate ook van bedrijven die betalingsregelingen treffen met hun klanten. Er is echter ook voor werkgevers een potentiële rol weggelegd bij de hulp aan werknemers met financiële problemen. Hoe staan werkgevers en werknemers daar tegenover