Geologiese tyd of oseaandiepte?

Die fossielelae van die paleontologie skep vir die natuur- wetenskaplike sowel as die teoloog oënskynlik onoorbrugbare vraagstukke. Vir die natuurwetenskaplike spreek dit van kronologiese opeenvolging van lewe op aarde ooreenkomstig 'n patroon wat oor die algemeen dui op ’n miljoene jare-proses van die primitiefste tot die mees ingewikkelde bouvorms. Hierdie verskynsel suggereer al dadelik die waarskynlikheid van ’n deurlopende evolusieproses wat oor miljarde jare vol- trek is. Die belangrikste vraagstuk waarvoor aanhangers van so ’n teorie te staan kom, is die algehele afwesigheid van oorgangsvorme wat tussen die verskillende fossielelae moes gevind gewees het indien daar sprake was van genetiese ver­ band. Op die verskillende uitvlugte hoef hier nie ingegaan te word nie, behalwe om prof. J. Lever aan te haal wat verklaar dat indien so ’n proses wel plaasgevind het, dit geskied het op ’n wyse wat vir die wetenskaplike tans nog onbekend is.1

Ontsporing van die regstaatsbegrip en sy konsekwensies vir die afrikanervolk

Die opvatting van die suiwere regstaat bring sy vraagstukke mee wanneer dit in verband gebring word met die leer van die soewereiniteit in eie kring. Laasgenoemde leer wortel in die geloof dat God die mens roep tot diens aan Hom, en dat die mens vry moet wees om ten opsigte van alle lewensaspekte God na die hoogste mate te kan dien. Hierdie verskeidenheid van aspekte is deur dr. A. Kuyper en sy volgelinge gesistemati- seer tot menslike verbande en lewenskringe, elk met ’n be- paalde sfeer waarin ander kringe nie mag inmeng nie. Elkeen is dan soewerein binne sy eie kring. Met verwysing na die staat is dan gespreek van die staatstaak as synde die hand- hawing van die reg, en omdat die staat in toenemende mate hom veral in die latere tyd ook besig gehou het met bedrywig- hede wat nouliks as van juridiese aard beskou kan word, is daar die onderskeid gemaak tussen die primêre en sekundêre taak van die staat. Die sistematiek van die wetsidee, deur prof. Dooyeweerd ontwikkel, waar die staat sy bestemmingsfunksie in die regsaspek vind, het vanselfsprekend geen plek vir so 'n dualistiese staatstaak nie, en die oplossing is deur sommige daarin gesoek om sulke staatsoptrede te vertolk as hebbende wel betrekking op die regsgemeenskap of die regsverkeer. Staatsondernemings soos paaie, spoorweë, spellingreëling, ens. word dan beskou as noodsaaklik vir die instandhouding van die regsgemeenskap en regsverkeer. Tereg wys A. M. Donner1) daarop dat so ’n vertolking eintlik neerkom op ’n oorspanning van die regsbegrip. Hy self sien dan die staatstaak in vrede- of orde-handhawing, wat in die eerste plaas wel regshandha- wing veronderstel. Onder orde word dan alles verstaan wat noodsaaklik is vir die gladde verkeer in die ontwikkelingsgang van die regsgemeenskap. Die wese van die staat het dan vol- gens hom te doen met reg, maar sy taak is meer as suiwere regshandhawing. Wat onrus verwek en die orde versteur, moet uit die openbare lewe verwyder word, en die behoefte aan orde en reëlmaat wat die staat moet bevredig, lê nie net op die juridiese nie, m aar ook op die ekonomiese, sosiale en kultu- rele terrein

A deep learning approach to diabetic blood glucose prediction

We consider the question of 30-minute prediction of blood glucose levels measured by continuous glucose monitoring devices, using clinical data. While most studies of this nature deal with one patient at a time, we take a certain percentage of patients in the data set as training data, and test on the remainder of the patients; i.e., the machine need not re-calibrate on the new patients in the data set. We demonstrate how deep learning can outperform shallow networks in this example. One novelty is to demonstrate how a parsimonious deep representation can be constructed using domain knowledge

A haemagglutination and a haemagglutination inhibition test for bluetongue virus

Haemagglutination of bluetongue virus (BTV) was demonstrated for the first time by making use of a purified preparation of the virus. The reaction was found to be independent of variations in the pH, temperature, buffer system and origin of the erythrocytes used in the test. A haemagglutination inhibition test, subsequently developed, was demonstrated to be serotype specific. The storage of the virus for indefinite periods was facilitated by lyophilization of BTV in the presence of a low concentration of sucrose.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Establishing and maintaining international collaborative research teams: an autobiographical insight

Despite the growing impetus for international collaborative research teams (ICRT), there are relatively few resources available to guide and support researchers through the processes of establishing and maintaining ICRTs. In particular, no articles were found that provided researchers’ firsthand accounts of being a member of such a team. Having access to such personal accounts can help both experienced and novice researchers learn more directly about what to expect, as well as the benefits, challenges, pitfalls, and success strategies for establishing and maintaining ICRTs. The authors used phenomenological autobiographical reflective journaling to capture their experiences as members of ICRTs. In this article we provide an overview of key themes that emerged from the analysis of our reflections as members of ICRTs. These themes include: benefits, challenges, and strategies for success. Our aim is to share our first-hand experiences of what it is like to establish and participate in ICRT. It is not our intention to provide readers with prescriptive guidelines on how to set up and maintain ICRTs. Every ICRT is unique and some of these ideas may or may not apply in every case. Instead, we are describing what worked for us, hoping that others may benefit from our experience. Consequently, we suggest that the focus of ICRT should be on the benefits thereof which promote and encourage interaction between disciplines, transfer of knowledge and techniques and personal and professional development.Web of Scienc

Evaluating the accuracy of diffusion MRI models in white matter

Models of diffusion MRI within a voxel are useful for making inferences about the properties of the tissue and inferring fiber orientation distribution used by tractography algorithms. A useful model must fit the data accurately. However, evaluations of model-accuracy of some of the models that are commonly used in analyzing human white matter have not been published before. Here, we evaluate model-accuracy of the two main classes of diffusion MRI models. The diffusion tensor model (DTM) summarizes diffusion as a 3-dimensional Gaussian distribution. Sparse fascicle models (SFM) summarize the signal as a linear sum of signals originating from a collection of fascicles oriented in different directions. We use cross-validation to assess model-accuracy at different gradient amplitudes (b-values) throughout the white matter. Specifically, we fit each model to all the white matter voxels in one data set and then use the model to predict a second, independent data set. This is the first evaluation of model-accuracy of these models. In most of the white matter the DTM predicts the data more accurately than test-retest reliability; SFM model-accuracy is higher than test-retest reliability and also higher than the DTM, particularly for measurements with (a) a b-value above 1000 in locations containing fiber crossings, and (b) in the regions of the brain surrounding the optic radiations. The SFM also has better parameter-validity: it more accurately estimates the fiber orientation distribution function (fODF) in each voxel, which is useful for fiber tracking

Prolactin, cortisol and thyroxine levels and the premature infant

The relationship of prolactin, cortisol and thyroxine values in cord and maternal plasma to fetal age and weight and to the incidence of hyaline membrane disease (HMD) was investigated in 80 neonates of whom 40 were born at more than 37 weeks' gestation. Of the 40 born at less than 36 weeks 11 developed HMD. Serum cortisol has been shown to be a differentiating factor for HMD, but cord thyroxine and prolactin levels seem to be related more to age and weight than to the occurrence of HMD

Variability monitoring of the hydroxyl maser emission in G12.889+0.489

Through a series of observations with the Australia Telescope Compact Array we have monitored the variability of ground-state hydroxyl maser emission from G12.889+0.489 in all four Stokes polarisation products. These observations were motivated by the known periodicity in the associated 6.7-GHz methanol maser emission. A total of 27 epochs of observations were made over 16 months. No emission was seen from either the 1612 or 1720 MHz satellite line transitions (to a typical five sigma upper limit of 0.2 Jy). The peak flux densities of the 1665 and 1667 MHz emission were observed to vary at a level of ~20% (with the exception of one epoch which dropped by <40%). There was no distinct flaring activity at any epoch, but there was a weak indication of periodic variability, with a period and phase of minimum emission similar to that of methanol. There is no significant variation in the polarised properties of the hydroxyl, with Stokes Q and U flux densities varying in accord with the Stokes I intensity (linear polarisation, P, varying by <20%) and the right and left circularly polarised components varying by <33% at 1665-MHz and <38% at 1667-MHz. These observations are the first monitoring observations of the hydroxyl maser emission from G12.889+0.489.Comment: 7 pages, 6 figures, accepted for publication in MNRA