The Multiple Insertion Pyramid: A Fast Parameter-Less Population Scheme

textabstractThe Parameter-less Population Pyramid (P3) uses a novel population scheme, called the population pyramid. This population scheme does not require a fixed population size, instead it keeps adding new solutions to an ever growing set of layered populations. P3 is very efficient in terms of number of fitness function evaluations but its runtime is significantly higher than that of the Gene-pool Optimal Mixing Evolutionary Algorithm (GOMEA) which uses the same method of exploration. This higher run-time is caused by the need to rebuild the linkage tree every time a single new solution is added to the population pyramid.We propose a new population scheme, called the multiple insertion pyramid that results in a faster variant of P3 by inserting multiple solutions at the same time and operating on populations instead of on single solutions

Bile Acid Malabsorption in Cystic Fibrosis; Membrane Vesicles, a Tool for Revealing the Role of the Ileal Brush Border Membrane

ABSTRACT. Increased fecal bile acid loss in cystic fibrosis (CF) may result from ileal dysfunction. A method to quantitate in vitro Na+‐dependent taurocholate uptake into brush border membrane vesicles prepared from frozen ileum and ileal biopsy specimen is described. This transport across the ileal brush border membrane can be measured selectively, in contrast to in vivo measurements which represent a complex overall process. Preliminary results obtained with ileal specimen of 2 CF patients, suggest that in vitro bile acid uptake is low but not abnormal. Copyrigh

Improving mobile video quality through predictive channel quality based buffering

Frequent variations in throughput make mobile networks a challenging environment for video streaming. Current video players deal with those variations by matching video quality to network throughput. However, this adaptation strategy results in frequent changes of video resolution and bitrate, which negatively impacts the users' streaming experience. Alternatively, keeping the video quality constant would improve the experience, but puts additional demand on the network. Downloading high quality content when channel quality is low requires additional resources, because data transfer efficiency is linked to channel quality. In this paper, we present a predictive Channel Quality based Buffering Strategy (CQBS) that lets the video buffer grow when channel quality is good, and relies on this buffer when channel quality decreases. Our strategy is the outcome of a Markov Decision Process. The underlying Markov chain is conditioned on 377 real-world LTE channel quality traces that we have collected using an Android mobile application. With our strategy, mobile network providers can deliver constant quality video streams, using less network resources

Prevalence of hyperinsulinaemia among normozoospermic donors at Medfem Clinic, South Africa

The aim of this study was to investigate the prevalence of hyperinsulinaemia in a group of normozoospermic donors and the influence of insulin levels on in vitro fertilisation (IVF) outcome. Fasting insulin and 2 h post-eating insulin levels were determined for a group of thirty-four sperm donors. They were divided into three groups according to their insulin profiles. The association between insulin levels and embryo quality was determined in a clinical study for the different groups. The prevalence of raised insulin in the donor group was 44% with a 95% confidence interval of 27.2% and 62.1%. Donors with normal insulin levels produced more good quality blastocysts in the IVF programme than those with abnormal insulin levels. These differences were not statistically significant (P = 0.8638). Embryo quality in an IVF programme may be influenced by male insulin levels. The role of insulin in male fertility needs to be investigated.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1439-0272hb2014ay201

The effect of injectable biocompatible elastomer (PDMS) on the strength of the proximal fixation of endovascular aneurysm repair grafts: An in vitro study

PurposeOne of the major concerns in the long-term success of endovascular aneurysm repair (EVAR) is stent graft migration, which can cause type I endoleak and even aneurysm rupture. Fixation depends on the mechanical forces between the graft and both the aortic neck and the blood flow. Therefore, there are anatomical restrictions for EVAR, such as short and angulated necks. To improve the fixation of EVAR grafts, elastomer (PDMS) can be injected in the aneurysm sac. The support given by the elastomer might prevent dislocation and migration of the graft. The aim of this study was to measure the influence of an injectable biocompatible elastomer on the fixation strength of different EVAR grafts in an in vitro model.MethodsThe proximal part of three different stent grafts was inserted in a bovine artery with an attached latex aneurysm. The graft was connected to a tensile testing machine, applying force to the proximal fixation, while the artery with the aneurysm was fixated to the setup. The force to obtain graft dislodgement (DF) from the aorta was recorded in Newtons (N). Three different proximal seal lengths (5, 10, and 15 mm) were evaluated. The experiments were repeated after the space between the graft and the latex aneurysm was filled with the elastomer. Independent sample ttests were used for the comparison between the DF before and after elastomer treatment for each seal length.ResultsThe mean DF (mean ± SD) of all grafts without elastomer sac filling for a proximal seal length of 5, 10, and 15 mm were respectively, 4.4 ± 3.1 N, 12.2 ± 10.6 N, and 15.1 ± 6.9 N. After elastomer sac filling, the dislodgement forces increased significantly (P < .001) to 20.9 ± 3.8 N, 31.8 ± 9.8 N, and 36.0 ± 14.1 N, respectively.ConclusionsThe present study shows that aneurysm sac filling may have a role as an adjuvant procedure to the present EVAR technique. The strength of the proximal fixation of three different stent grafts increases significantly in this in vitro setting. Further in vivo research must be done to see if this could facilitate the treatment of aneurysms with short infrarenal necks.Clinical RelevanceStent graft migration and endoleak due to suboptimal fixation are major drawbacks of currently available stent grafts. Optimizing the proximal fixation by peri-graft elastomer aneurysm sac filling may lead to lower incidence of graft migration and endoleak. It might make endovascular aneurysm repair available to larger group of patients with an abdominal aortic aneurysm

Preparation of microscaner data and core photos for joint analysis and linking

Vascular Surger

Studies on the Cold Injury of the Chestnut Tree 1 : The Change of Moisture, Respiration and Osmotic pressure during the winter

Moisture and respiration of the stems of chestnut trees and osmotic pressure of their living bark cells were investigated at various times during the period from Oct. 1956 to Mar. 1957. The stems of on-year-old chestnut trees and their stocks (Gin-yose seedlings) were chiefly used as the materials. During the investigation the water content of a sweet chestnut variety (less hardy) was a little higher than that of Japanese chestnut varieties (semi-hardy). In December, the amount of CO_2 output from the stems in Japanese chestnut varieties was less han sweet chestnut variety. In January, however, the difference among them was hardly observed. In all varieties, the respiration of the stems decreased and the osmotic pressure (with incipient plasmolysis) of the living bark cells increased rapidly from the late fall, and attained respectively to certain levels, particularly the harder varieties reached earlier. The osmotic pressure of the living bark cells of the trunk of two or three years' old, decreased gradually from the top to base

Cerebellar potentiation and learning a whisker-based object localization task with a time response window

Whisker-based object localization requires activation and plasticity of somatosensory and motor cortex. These parts of the cerebral cortex receive strong projections from the cerebellum via the thalamus, but it is unclear whether and to what extent cerebellar processing may contribute to such a sensorimotor task. Here, we subjected knock-out mice, which suffer from impaired intrinsic plasticity in their Purkinje cells and long-term potentiation at their parallel fiber-to-Purkinje cell synapses (L7-PP2B), to an object localization task with a time response window (RW). Water-deprived animals had to learn to localize an object with their whiskers, and based upon this location they were trained to lick within a particular period ("go" trial) or refrain from licking ("no-go" trial). L7-PP2B mice were not ataxic and showed proper basic motor performance during whisking and licking, but were severely impaired in learning this task compared with wild-type littermates. Significantly fewer L7-PP2B mice were able to learn the task at long RWs. Those L7-PP2B mice that eventually learned the task made unstable progress, were significantly slower in learning, and showed deficiencies in temporal tuning. These differences became greater as theRWbecame narrower. Trained wild-type mice, but not L7-PP2B mice, showed a net increase in simple spikes and complex spikes of their Purkinje cells during the task. We conclude that cerebellar processing, and potentiation in particular, can contribute to learning a whisker-based object localization task when timing is relevant. This study points toward a relevant role of cerebellum- cerebrum interaction in a sophisticated cognitive task requiring strict temporal processing

Cerebellar control of gait and interlimb coordination

Synaptic and intrinsic processing in Purkinje cells, interneurons and granule cells of the cerebellar cortex have been shown to underlie various relatively simple, single-joint, reflex types of motor learning, including eyeblink conditioning and adaptation of the vestibulo-ocular reflex. However, to what extent these processes contribute to more complex, multi-joint motor behaviors, such as locomotion performance and adaptation during obstacle crossing, is not well understood. Here, we investigated these functions using the Erasmus Ladder in cell-specific mouse mutant lines that suffer from impaired Purkinje cell output (Pcd), Purkinje cell potentiation (L7-Pp2b), molecular layer interneuron output (L7-Δγ2), and granule cell output (α6-Cacna1a). We found that locomotion performance was severely impaired with small steps and long step times in Pcd and L7-Pp2b mice, whereas it was mildly altered in L7-Δγ2 and not significantly affected in α6-Cacna1a mice. Locomotion adaptation triggered by pairing obstacle appearances with preceding tones at fixed time intervals was impaired in all four mouse lines, in that they all showed inaccurate and inconsistent adaptive walking patterns. Furthermore, all mutants exhibited altered front–hind and left–right interlimb coordination during both performance and adaptation, and inconsistent walking stepping patterns while crossing obstacles. Instead, motivation and avoidance behavior were not compromised in any of the mutants during the Erasmus Ladder task. Our findings indicate that cell type-specific abnormalities in cerebellar microcircuitry can translate into pronounced impairments in locomotion performance and adaptation as well as interlimb coordination, highlighting the general role of the cerebellar cortex in spatiotemporal control of complex multi-joint movements