Portable X-ray fluorescence of zinc applied to human toenail clippings

Zinc is an essential trace element in humans. Zinc deficiency can result in a range of serious medical conditions which include effects on growth and development, the immune system, the central nervous system, and the gastrointestinal system. Diagnosis of zinc deficiency is often precluded by the lack of a noninvasive and reliable biomarker. Zinc concentration in nail is considered an emerging biomarker of zinc status in humans. Whether zinc in nail accurately reflects zinc status is beyond the scope of the current study, but is an important research question. The development of a portable method to quickly assess zinc concentration from a single nail clipping could be a useful advance. In this study, single toenail clippings from 60 individuals living in Atlantic Canada were measured for zinc using a portable X-ray fluorescence (XRF) technique. These samples were obtained from the Atlantic PATH cohort, part of the largest chronic disease study ever performed in Canada. Each toenail clipping was measured using three 300 s trials with a mono-energetic portable XRF system. Results were then assessed using two different approaches to the XRF analysis: (1) factory-calibrated zinc concentrations were output from each trial, and (2) energy spectra were analyzed for the characteristic X-rays resulting from zinc. Following the measurement of zinc using the non-destructive portable XRF method, the same clippings were measured for zinc concentration using the “gold standard” technique of inductively coupled plasma-mass spectrometry (ICP-MS). A linear equation of best fit was determined for the relationship between average XRF output zinc concentration and ICP-MS zinc concentration, with a correlation coefficient r = 0.60. Similarly, a linear equation of best fit was found for the relationship between a normalized XRF energy spectrum zinc signal and ICP-MS zinc concentration, with a correlation coefficient r = 0.68. Individual ICP-MS zinc concentrations ranged from 32 μg/g to 140 μg/g, with a population average of 85 μg/g. The results of this study indicate that portable XRF is a sensitive method for the measurement of zinc in a single nail clipping, and provides a reasonable estimation of zinc concentration. Further method development is required before portable XRF be considered a routine alternative to ICP-MS for the assessment of zinc in nail clippings.     

Variation in enamel development of South African fossil hominids

Dental tissues provide important insights into aspects of hominid palaeobiology that are otherwise difficult to obtain from studies of the bony skeleton. Tooth enamel is formed by ameloblasts, which demonstrate daily secretory rhythms developing tissue-specific structures known as cross striations, and longer period markings called striae of Retzius. These enamel features were studied in the molars of two well known South African hominid species, Australopithecus africanus and Paranthropus robustus. Using newly developed portable confocal microscopy, we have obtained cross striation periodicities (number of cross striations between adjacent striae) for the largest sample of hominid teeth reported to date. These data indicate a mean periodicity of seven days in these small-bodied hominids. Important differences were observed in the inferred mechanisms of enamel development between these taxa. Ameloblasts maintain high rates of differentiation throughout cervical enamel development in P. robustus but not in A. africanus. In our sample, there were fewer lateral striae of Retzius in P. robustus than in A. africanus. In a molar of P. robustus, lateral enamel formed in a much shorter time than cuspal enamel, and the opposite was observed in two molars of A. africanus. In spite of the greater occlusal area and enamel thickness of the molars of both fossil species compared with modern humans, the total crown formation time of these three fossil molars was shorter than the corresponding tooth type in modern humans. Our results provide support for previous conclusions that molar crown formation time was short in Plio-Pleistocene hominids, and strongly suggest the presence of different mechanisms of amelogenesis, and thus tooth development, in these taxa.     

Efficacy and accuracy of portable PIT-antennae when locating fish in ice-covered streams

Active tracking of passive integrated transponder (PIT)-tags using portable antennae is becoming an increasingly common technique in fish habitat studies in shallow rivers. We carried out “blind testing” to test the efficacy (% tags found) and accuracy (distance between predicted and true tag location) of a portable antenna system (Texas Instruments) in winter conditions using 23-mm PIT-tags. Up to 90 cm reading range was achieved and signals penetrated ice, rock, wood and water. In the “blind test” trials, a majority of the hidden tags (N = 12–30) were found indicating high tracking efficacy. PIT-tags that were oriented with their cylindrical axis parallel to the plane of the antenna coil inductor loop resulted in a bimodal detection field that had low detection range in the centre of the loop. The utilization of this bimodal detection field proved to be a very accurate method for identifying tag position (mean ± SE distance from predicted to true tag location 10.9 ± 1.4 cm) and thus well suited for microhabitat and activity studies in winter conditions. Aggregations of tags (multiple tags within 1 m²) and obstacles for the antenna maneuvering (e.g., boulders, logjams) reduced the pinpointing accuracy (mean ± SE 13.3 ± 1.8 cm), but the reduction in accuracy was statistically non-significant between the single and aggregated tags.     

基于蓝牙4.0的便携式睡眠监测仪的研制

目的:实时监测睡眠状况,从而帮助人们特别是老人找到影响睡眠的原因。方法:设计了一个低功耗便携式睡眠监测仪,它是通过加速度传感器采集腕动信号、蓝牙4.0低功耗无线传输、Micro-SD卡存储、上位机显示等实现对睡眠状态的检测。为了验证睡眠监测仪的准确性,本文采用了视频分析方法,并且对不同人群进行监测。结果:研制的睡眠监测仪具有便携低功耗等特点,能够准确监测睡眠状态。结论:睡眠监测仪的研制对使用者特别是老人帮助很大,能够帮助使用者方便适时了解自己的睡眠状况,找到影响睡眠原因和改善睡眠质量方法。     

Nouvelles données sur le Magdalénien inférieur de la Région Cantabrique : le Niveau F de la grotte de El Cierro (Ribadesella,Asturies, Espagne)

El Cierro Cave (Ribadesella, Asturias, Spain), located near the mouth of the River Sella, has yielded one of the most important Upper Palaeolithic sequences in northern Spain. To date, three major occupation periods at the cave have been identified and dated. The first was at the beginning of the Holocene (ca. 8500 BP; ca. 9000 cal BP); the second at the end of the Upper Palaeolithic, in the Younger Dryas (YD) or Greenland Stadial 1 (GS1) (ca. 11.200 BP; 12.700 cal BP) and the third during Greenland Stadial 2 (GS2) (ca. 16.300–15.500 BP; ca. 19.200–18.700 cal BP). This paper describes the stratigraphy documented in the excavations performed by F. Jordá Cerdá and A. Gómez-Fuentes between 1977 and 1979 and presents the first radiocarbon determinations for the first two occupation periods, together with the study of the archaeological materials found in Level F. This level, dated to 15.500 BP (ca. 18.700 cal BP) is characterised by specialised red deer hunting and the gathering of marine resources (winkles). Various artefacts made from animal raw materials have been documented; both finished products and items in the process of being manufactured, as well as portable art objects. The lithic assemblage, consisting mainly of local raw materials with a small proportion of allochthonous flint, is characterised by an abundance of small bladelet cores and backed bladelets. These archaeological remains and the radiocarbon date mean Level F can be attributed to the so-called “Cantabrian Lower Magdalenian”. This period has been documented archaeologically and dated to a similar time at other sites in the River Sella valley and in the rest of northern Spain.     

Smell intensity monitoring using metal oxide semiconductor odor sensors during intravenous olfaction test

The intravenous olfaction test using prosultiamine (PST) solution is simple to perform and has been used clinically in Japan. We monitored intranasal intensity of smell continuously in real time under various conditions of administration using metal oxide semiconductor odor sensors and established an optimal PST injection procedure. In this study, we found that 1) although there was fluctuation in the pattern of intensity of increase in smell in the PST original solution test, the pattern of increase in intranasal smell intensity could be stabilized by prolonging the injection time to 40 s and 2) dilution of PST with physiological saline was effective in preventing angialgia during intravenous injection. It appears that PST administration is best performed by adding 10 ml of saline to 10 mg (2 ml) of PST and injecting the resulting 12-ml solution (6x dilution) and that the best respiratory cycle for testing is once in every 2 s.     

Modification and field testing of a portable gas chromatograph forin situ acetylene reduction activity assay of tropical soils

Summary Small modifications of the Mallard/Holfeld/LaRue GC allow indirect measurement of biological N₂-fixation in tropical soils even in remote locations. Examples of ARA from Philippine rice fields are given.     

On the design of a flexible stimulator for animal studies in auditory prostheses

The present paper describes the design of two stimulators (bench-top and portable) which can be used for animal studies in cochlear implants. The bench-top stimulator is controlled by a high-speed digital output board manufactured by National Instruments and is electrically isolated. The portable stimulator is controlled by a personal digital assistant (PDA) and is based on a custom interface board that communicates with the signal processor in the PDA through the secure digital IO (SDIO) slot. Both stimulators can provide 8 charge-balanced, bipolar channels of pulsatile and analog-like electrical stimulation, delivered simultaneously, interleaved or using a combination of both modes. Flexibility is provided into the construction of arbitrary, but charge-balanced, pulse shapes, which can be either symmetric or asymmetric.     

La découverte d’un galet gravé du Paléolithique final dans la région du Haut Iénisséï (Sibérie du Sud)

The paper deals with the artifact found during the realization of a salvage archaeological project connected with the construction of the railway from Kyzyl to Kuragino (the Krasnoyarsk Region, South Siberia) in 2012. During the exploration of the multicomponent habitation site of Irba 2 below the Holocene cultural strata the Pleistocene remains have been unearthed. These include bones of bison, reindeer, red deer, giant deer, wild horse, brown bear and hare, lithics, and pieces of worked antler. Radiocarbon dates indicate the Final Pleistocene age (ca. 13 to 11 kyr BP). The assemblage belongs to the Afontova culture dominated in the upper reaches of Yenisei during the Final Upper Paleolithic. The rare finding, an unique engraved oval-shaped flat pebble of white marble is worth to mention. It has 37 lateral grooves, cross-shaped engravings in the central parts of both lateral surfaces and traces of unfinished hollows. The nearest analogs are agalmatolite discs from the sites of Afontova Gora II and III located at Krasnoyarsk. These findings are rare in the Paleolithic and could be considered as amulets.     

CHANGES IN CELLULAR PROTEINS DUE TO ENVIRONMENTAL NON-IONIZING RADIATION. I. HEAT-SHOCK PROTEINS

This paper describes the effect of weak microwave fields on the amounts of heat-shock proteins in cell cultures at various temperatures.

The field was generated by signal simulation of the Global System for Mobile communications (GSM) of 960 Mhz, used in portable phones. Transformed human epithelial amnion (AMA) cells, growing on glass coverslips, were exposed in a transverse electromagnetic (TEM) cell to a microwave field, generating a specific absorption rate (SAR) of 2.1 mW.kg^?1 in the cells. Exposure temperatures were 35, 37, and 40 ± 0.1°C, respectively, and the exposure time was 20 min.

The heat-shock proteins Hsp-70 and Hsp-27 were detected by immuno-fluorescence. Higher amounts of Hsp-70 were present in the cells exposed at 35 and 37°C than in the sham-exposed cells.

These effects can be considered to be athermal, since the field strength was much lower than the safety standard for absence of heat generation by microwave fields.

There was no significant response in the case of Hsp-27.