Small-sized Samples Research Articles

The use of animals in Northern Mesoamerica, between the Classic and the Conquest (200-1521 AD). An attempt at regional synthesis on central Mexico

Zooarchaeology of Northern Mesoamerica has often been restricted to major archaeological sites and few regional syntheses are documented. Based on the original analysis of animal bone remains from ten archaeological assemblages and their confrontation with iconographic, historic and ethnographic data, this paper aims to propose a synthesis on the use of animals in central Mexico, from the Classic period to the Spanish Conquest. We selected sites from a similar environment but two cultural regions: Central Mexico and Western Mexico. The methodology used to compare the results from each assemblage is adapted to a particularly heterogeneous corpus and small-sized samples. The identification of 35 different taxa shows the use of a restricted and rather homogeneous spectrum. However variations are observed considering their proportions in each site. Only two domestic animals are recognised, the dog (Canis familiaris Linnaeus, 1758) and the turkey (Meleagris gallopavo Linnaeus, 1758), but none of the studied societies specialised in the breeding of these species. We then address the cases of hunting or garden-hunting and the exploitation of aquatic animals. Finally, hypotheses are presented about how the animals were used by the populations of Nothern Mesoamerica. Although a larger number of sites need to be studied to enhance the impact of our interpretations, this paper establishes a first attempt at regional synthesis on central Mexico.

A Bayesian Virtual Metrology for Quality Inspection of Mobile Repeater Systems

Abstract The technology of wideband code division multiple access (WCDMA) has been applied to band selective interference cancellation system (ICS) repeaters. To inspect the telecommunication quality of the systems, quality engineers must check the shape of the signals at the corresponding frequency band of the repeaters. However, measuring the signal quality is a repetitive manual task which requires much inspection time and high costs. In the case of small-sized samples, such as the example of an ICS repeater system, Bayesian approaches have been employed to improve the estimation accuracy by incorporating prior information on the parameters of the model in consideration. This research proposes a virtual method of quality inspection for products using a correlation structure of measurement data, mainly in a Bayesian regression framework. The Bayesian regression model derives prior information from historical measurement data to predict measurements of other frequency bandwidths by exploiting the correlation structure of each measurement data. Empirical results show the potential for reducing inspection costs and time by predicting the values of adjoining frequency bandwidths through measured data of a frequency bandwidth in the course of quality inspections of ICS repeater systems.

Characterization of Initial Parameter Information for Lifetime Prediction of Electronic Devices

Newly manufactured electronic devices are subject to different levels of potential defects existing among the initial parameter information of the devices. In this study, a characterization of electromagnetic relays that were operated at their optimal performance with appropriate and steady parameter values was performed to estimate the levels of their potential defects and to develop a lifetime prediction model. First, the initial parameter information value and stability were quantified to measure the performance of the electronics. In particular, the values of the initial parameter information were estimated using the probability-weighted average method, whereas the stability of the parameter information was determined by using the difference between the extrema and end points of the fitting curves for the initial parameter information. Second, a lifetime prediction model for small-sized samples was proposed on the basis of both measures. Finally, a model for the relationship of the initial contact resistance and stability over the lifetime of the sampled electromagnetic relays was proposed and verified. A comparison of the actual and predicted lifetimes of the relays revealed a 15.4% relative error, indicating that the lifetime of electronic devices can be predicted based on their initial parameter information.

Noncontact Measurement of Complex Permittivity of Electrically Small Samples at Microwave Frequencies

Noncontact measurements of material parameters have important applications in various fields. In this paper, we propose a noncontact measurement of complex permittivity for electrically small samples at microwave frequencies. Based on Rayleigh approximation, we propose a noncontact measurement approach that can linearly retrieve complex permittivity from the measured impedance change. Using a subwavelength resonance, far-field radiation can be effectively suppressed, and thus the measurement is not notably influenced by unwanted environmental reflection. With the features of simple calibration and noncontact measurement, our method can be widely used in repeated on-site measurements of complex permittivity for small-sized samples at microwave frequencies.

Study of Factors Determinant of Siliceous Electrical Porcelain Resistance to Structural Degradation

Abstract The subject of this study was investigation of the factors that have a decisive influence on the resistance of siliceous porcelain to degradation processes. There was tested material C 110 type, which is widely used for the production of low-voltage (LV) elements such as insulators and bushings. On the basis of mechanical-acoustic and microscopic research of small-sized samples, which were subjected to compression, there were distinguished successive stages of degradation of the material structure. In the authors’ opinion, they have a reference to the ageing process, taking place during many years of work under operating conditions. Thus, it was possible to assess the structural factors that determine the durability and reliability of LV electroinsulating elements. The results were related to electrical aluminous porcelains.

Mass spectrometric phosphoproteome analysis of small-sized samples of human neutrophils

BackgroundGlobal analysis of stimulus-dependent changes in the neutrophil phosphoproteome will improve the understanding of neutrophil signal transduction and function in diverse disease settings. However, gel-free phosphoproteomics of neutrophils in clinical studies is hampered by limited sample amounts and requires protein extract stability, efficient tryptic digestion and sensitive phosphopeptide enrichment in a protease-rich environment. For development of an appropriate workflow, we assessed neutrophil protein stability in urea-based lysis buffers and determined feasibility of gel-free phosphoproteomic analyses using polymer-based metal ion affinity capture (PolyMAC). MethodsWestern blotting, phosphopeptide enrichment and mass spectrometric analyses of samples of neutrophils were performed. ResultsDegradation of proteins in neutrophil extracts was observed after preparation with a urea-containing lysis buffer and could be prevented by addition of highly concentrated protease inhibitors. Subsequent tryptic digestion and PolyMAC-based phosphopeptide enrichment proved efficient with accordingly prepared neutrophil samples. Applying the new workflow, formyl–methionyl–leucyl–phenylalanine-induced phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) was detected after gel-free and gel-based phosphoproteomic analyses as proof of principle from 20ml of whole blood. Furthermore, phosphorylation of other ERK1/2 pathway-associated proteins was monitored. ConclusionWe provide a workflow for efficient, gel-free phosphoproteome analyses with small-sized neutrophil samples, suitable for application in clinical studies.

Nanostructured Ti–Ni Shape Memory Alloys Produced by Thermomechanical Processing

This article describes the evolution of structural and functional properties of Ti–Ni SMA as a result of thermomechanical processing combining cold/warm deformation ranging from moderate to severe and post-deformation annealing at different temperatures. This study results in the development of an original thermomechanical processing route capable of producing truly nanocrystalline Ti–Ni SMA with grain size ranging from 40 to 80 nm. These structures are mainly a result of crystallization at moderate temperatures of the alloys subjected to severe “amorphizing” cold rolling. A clear demonstration is made that the nanocrystalline structures are the most favorable structures, compared to their recrystallized and polygonized counterparts, for the practical application of Ti–Ni alloys from the viewpoint of their static and dynamic functional characteristics. Despite the fact that these results were obtained on relatively small-sized samples (0.2…0.7 mm thick, 3…5 mm wide cold/warm-rolled ribbons), they bring a clear understanding of the underlying processing-structure-properties interrelations, and, therefore, pave the way for the oncoming production of large-size nanocrystalline Ti–Ni SMA with a radically improved combination of functional characteristics.

Comparison of manual and semi-automatic DNA extraction protocols for the barcoding characterization of hematophagous louse flies (Diptera: Hippoboscidae)

The barcoding of life initiative provides a universal molecular tool to distinguish animal species based on the amplification and sequencing of a fragment of the subunit 1 of the cytochrome oxidase (COI) gene. Obtaining good quality DNA for barcoding purposes is a limiting factor, especially in studies conducted on small-sized samples or those requiring the maintenance of the organism as a voucher. In this study, we compared the number of positive amplifications and the quality of the sequences obtained using DNA extraction methods that also differ in their economic costs and time requirements and we applied them for the genetic characterization of louse flies. Four DNA extraction methods were studied: chloroform/isoamyl alcohol, HotShot procedure, Qiagen DNeasy(®) Tissue and Blood Kit and DNA Kit Maxwell(®) 16LEV. All the louse flies were morphologically identified as Ornithophila gestroi and a single COI-based haplotype was identified. The number of positive amplifications did not differ significantly among DNA extraction procedures. However, the quality of the sequences was significantly lower for the case of the chloroform/isoamyl alcohol procedure with respect to the rest of methods tested here. These results may be useful for the genetic characterization of louse flies, leaving most of the remaining insect as a voucher.

Choosing the Best Method for Gene Expression log- log Linear Models Using Multiple CART Trees

Microarray and RNA-Seq techniques are used to infer genes showing differential expressions on treatment conditions through the analysis of log-log linear models for the expression with treatment compared with control condition. Due to costs and technical limitations usually the experiments present small-sized samples and high contamination; therefore, choosing the estimation method for coefficients of such models becomes a challenge [1]. Herein, we simulate microarray and RNA-Seq experiments and analyze a log-log linear model with contaminations at both conditions, varying key features: the sample size n, contamination type (light-tailed or heavy-tailed), contamination proportion p, and error variance. For each features configuration we computed the accuracy at each method among least absolute deviations, ordinary least squares, and Huber M-Estimators. Using this information, we built a machine learning that, based on classification CART trees [2], automatically decides the best method depending on simple questions. ...

Atomic picture of elastic deformation in a metallic glass.

The tensile behavior of a Ni60Nb40 metallic glass (MG) has been studied by using ab initio density functional theory (DFT) calculation with a large cell containing 1024 atoms (614 Ni and 410 Nb). We provide insight into how a super elastic limit can be achieved in a MG. Spatially inhomogeneous responses of single atoms and also major polyhedra are found to change greatly with increasing external stress when the strain is over 2%, causing the intrinsically viscoelastic behavior. We uncover the origin of the observed super elastic strain limit under tension (including linear and viscoelastic strains) in small-sized MG samples, mainly caused by inhomogeneous distribution of excess volumes in the form of newly formed subatomic cavities.

Hypothetical Mechanism of Aspirin-Exacerbated Respiratory Disease Based on Recent Investigations of Gene Polymorphisms in Japanese Patients

Aspirin-exacerbated respiratory disease (AERD) is characterized by severe asthmatic attack after taking aspirin and/or nonsteroidal anti-inflammatory drugs (NSAIDs). The typical patient with AERD is an adult who develops refractory chronic rhinitis in the third or fourth decade of life. Natural history and clinical features of AERD indicates that during the evaluation of chronic rhinitis persistent bronchial asthma develops, and finally after exposure to NSAID acute respiratory reactions begin to occur. The inhibitory action of aspirin and/or NSAIDs on cyclooxygenase activity may cause diversion to the 5-lipoxygenase pathway, which leads to the overproduction of cysteinyl leukotrienes (LTs). Thus, a general consensus exists that increased levels of cysteinyl LTs are key inflammatory mediators in AERD. As aspirin intolerance is found in a specific population, genetic predisposition has been considered as a crucial determinant. Investigations on candidate genes have been concentrated especially on cysteinyl LTs-related genes, however conflicting results have been reported. So, future areas of investigations need to focus on comprehensive approaches towards other genetic biomarkers. We’ve recently reported possible presence of other gene polymorphisms in Japanese patients with AERD. The natural history and clinical characteristics of AERD indicate that the respiratory mucosal inflammatory process in AERD begins and continues in the absence of ongoing or even intermittent exposure to NSAIDs. So, in this review, we propose a hypothetical progress of AERD over time based on mainly the results of our investigations, and present a schematically sketching the course of NSAIDs-triggered hypersensitivity with genes, such as asthma-associated genes, that may initiate susceptibility to AERD, and that may accelerate pathogenesis and induce onset of AERD. The findings of our studies were based on small-sized samples from a Japanese population, and future validation studies in independent populations are required to provide reassurance about our hypothesis.

Plasticity and thermal recovery of thin copper wires in torsion

Experiments in small-scale plasticity usually focus on small-sized samples. However, studying thin wires with lengths up to metres in torsion has the advantage of giving extremely high strain resolution and reversal of the loading direction. In this way, we explore the early stage of plasticity. Microstrain plastic deformation, dislocation creep and the Bauschinger effects are easily observed. The onset of irreversible deformation was observed and associated with a few dislocations in the largest grains throughout the wire. Easy plastic deformation on reversal of the loading direction was observed following this initial plastic deformation but not before.

Quantitative dynamic modelling of the gene regulatory network controlling adipogenesis.

Gene regulatory networks (GRNs) coherently coordinate the expressions of genes and control the behaviors of cellular systems. The complexity in modeling a quantitative GRN usually results from inaccurate parameter estimation, which is mostly due to small sample sizes. For better modeling of GRNs, we have designed a small-sample iterative optimization algorithm (SSIO) to quantitatively model GRNs with nonlinear regulatory relationships. The algorithm utilizes gene expression data as the primary input and it can be applied in case of small-sized samples. Using SSIO, we have quantitatively constructed the dynamic models for the GRNs controlling human and mouse adipogenesis. Compared with two other commonly-used methods, SSIO shows better performance with relatively lower residual errors, and it generates rational predictions on the adipocyte responses to external signals and steady-states. Sensitivity analysis further indicates the validity of our method. Several differences are observed between the GRNs of human and mouse adipocyte differentiations, suggesting the differences in regulatory efficiencies of the transcription factors between the two species. In addition, we use SSIO to quantitatively determine the strengths of the regulatory interactions as well as to optimize regulatory models. The results indicate that SSIO facilitates better investigation and understanding of gene regulatory processes.

Large sample area and size are needed for forest soil seed bank studies to ensure low discrepancy with standing vegetation.

A large number of small-sized samples invariably shows that woody species are absent from forest soil seed banks, leading to a large discrepancy with the seedling bank on the forest floor. We ask: 1) Does this conventional sampling strategy limit the detection of seeds of woody species? 2) Are large sample areas and sample sizes needed for higher recovery of seeds of woody species? We collected 100 samples that were 10 cm (length) ×10 cm (width) ×10 cm (depth), referred to as larger number of small-sized samples (LNSS) in a 1 ha forest plot, and placed them to germinate in a greenhouse, and collected 30 samples that were 1 m×1 m×10 cm, referred to as small number of large-sized samples (SNLS) and placed them (10 each) in a nearby secondary forest, shrub land and grass land. Only 15.7% of woody plant species of the forest stand were detected by the 100 LNSS, contrasting with 22.9%, 37.3% and 20.5% woody plant species being detected by SNLS in the secondary forest, shrub land and grassland, respectively. The increased number of species vs. sampled areas confirmed power-law relationships for forest stand, the LNSS and SNLS at all three recipient sites. Our results, although based on one forest, indicate that conventional LNSS did not yield a high percentage of detection for woody species, but SNLS strategy yielded a higher percentage of detection for woody species in the seed bank if samples were exposed to a better field germination environment. A 4 m2 minimum sample area derived from power equations is larger than the sampled area in most studies in the literature. Increased sample size also is needed to obtain an increased sample area if the number of samples is to remain relatively low.

Geostatistical mapping of real estate prices: an empirical comparison of kriging and cokriging

Small-sized housing samples and price predictions at nonobserved locations require geostatistical approaches, particularly the kriging estimator. Nevertheless, geostatistics has thus far received little attention in real estate economics. The article’s objective is to empirically compare the prediction accuracy of univariate kriging variants, namely detrended kriging (DK) and universal kriging (UK), and multivariate extensions, including detrended cokriging (DCK) and universal cokriging (UCK). Both latter methods consider structural and neighborhood characteristics as auxiliary variables. While the price surfaces of DK and UK show nearly identical cross-validated accuracies, the cross-validation-based prediction accuracy of DCK and UCK differ in favor of the latter. If real estate agencies are faced with a univariate sample of property prices, either DK or UK can be used, while in the multivariate case, UCK is recommended, although numerically more complex.

Identification of miR-423 and miR-499 polymorphisms on affecting the risk of hepatocellular carcinoma in a large-scale population.

MicroRNAs (miRNAs) regulate gene expression and act as tumor suppressors or enhancers in oncogenesis. Single-nucleotide polymorphisms (SNPs) in miRNAs could alter the processing or actions of mature miRNA. So far, the association of miR-423 rs6505162 with cancers has not been explored, while the association of miR-499 rs3746444 was only reported in small-sized samples of different types of populations. To evaluate the association of miR-499 rs3746444 and miR-423 rs6505162 with hepatocellular carcinoma (HCC), we performed a large-scale case-control study of 984 patients with HCC and 991 cancer-free controls. The risk of HCC was significantly higher with miR-499 rs3746444 TC+CC genotypes compared with those with the TT genotype (odds ratio [OR]=1.372, 95% confidence intervals [CI]=1.099-1.713, p=0.005), as was the risk of hepatitis B virus-related HCC (OR=1.437, 95% CI=1.128-1.831, p=0.003). Moreover, subjects with the TC+CC genotypes were more vulnerable to advanced HCC with larger tumor size (χ(2)=13.014, p=0.001) and/or higher total bilirubin (p=0.004), which suggested that a TT genotype or T allele might serve as a protective factor. miR-423 rs6505162 had no effect on the risk of HCC. miR-499 rs3746444 may contribute to the risk and prognosis of HCC, indicating that this SNP could be developed as a biomarker for HCC prediction.

Identification of temporal variations in mental workload using locally-linear-embedding-based EEG feature reduction and support-vector-machine-based clustering and classification techniques

Identifying the abnormal changes of mental workload (MWL) over time is quite crucial for preventing the accidents due to cognitive overload and inattention of human operators in safety-critical human–machine systems. It is known that various neuroimaging technologies can be used to identify the MWL variations. In order to classify MWL into a few discrete levels using representative MWL indicators and small-sized training samples, a novel EEG-based approach by combining locally linear embedding (LLE), support vector clustering (SVC) and support vector data description (SVDD) techniques is proposed and evaluated by using the experimentally measured data. The MWL indicators from different cortical regions are first elicited by using the LLE technique. Then, the SVC approach is used to find the clusters of these MWL indicators and thereby to detect MWL variations. It is shown that the clusters can be interpreted as the binary class MWL. Furthermore, a trained binary SVDD classifier is shown to be capable of detecting slight variations of those indicators. By combining the two schemes, a SVC–SVDD framework is proposed, where the clear-cut (smaller) cluster is detected by SVC first and then a subsequent SVDD model is utilized to divide the overlapped (larger) cluster into two classes. Finally, three-class MWL levels (low, normal and high) can be identified automatically. The experimental data analysis results are compared with those of several existing methods. It has been demonstrated that the proposed framework can lead to acceptable computational accuracy and has the advantages of both unsupervised and supervised training strategies.

Size-dependent fracture toughness of bulk metallic glasses

The fracture toughness is a critical material property that determines engineering performance. However, as is well known for crystalline materials, if certain sample geometry and size requirements are not met, test results become sample-size dependent and difficult to compare between different studies. Here, the room-temperature fracture toughness of the Zr-based bulk metallic glass (BMG) Zr52.5Cu17.9Ni14.6Al10Ti5 (Vitreloy 105) was evaluated using compact-tension, as well as single-edge notched-bend, specimens of different sizes to measure KIc values according to ASTM standard E399 and JIc values according to ASTM standard E1820. It is concluded that the ASTM standard E399 sample-size requirements should be cautiously accepted as providing size-independent (valid) KIc results for BMGs; however, it is also concluded that small-sized samples may result in a wider scatter in conditional toughness KQ values, a smaller yield of valid tests and possibly somewhat elevated toughness values. Such behavior is distinct from crystalline metals where the size requirements of ASTM standard E399 are quite conservative. For BMGs, KQ values increase and show a larger scatter with decreasing uncracked ligament width b, which is also distinct from crystalline metals. Samples smaller than required by ASTM standards for KIc testing are allowed by the J-integral-based standard E1820; however, in this study on BMGs, such tests were found to give significantly higher toughness values as compared to valid KIc results. Overall, the toughness behavior of BMGs is more sensitive to size requirements than for crystalline metals, an observation that is likely related to the distinct size-dependent bending ductility and strain softening behavior found for metallic glasses. It is concluded that toughness values measured on BMG samples smaller than that required by the KIc standard, which are common in the literature, are likely sample size- and geometry-dependent, even when they meet the less restrictive valid JIc requirements.

A miniaturized solid contact test with Arthrobacter globiformis for the assessment of the environmental impact of silver nanoparticles

Silver nanoparticles (AgNPs) are widely applied for their antibacterial activity. Their increasing use in consumer products implies that they will find their way into the environment via wastewater-treatment plants. The aim of the present study was to compare the ecotoxicological impact of 2 differently designed AgNPs using the solid contact test for the bacterial strain Arthrobacter globiformis. In addition, a miniaturized version of this test system was established, which requires only small-sized samples because AgNPs are produced in small quantities during the design level. The results demonstrate that the solid contact test can be performed in 24-well microplates and that the miniaturized test system fulfills the validity criterion. Soils spiked with AgNPs showed a concentration-dependent reduction of Arthrobacter dehydrogenase activity for both AgNPs and Ag ions (Ag(+)). The toxic effect of the investigated AgNPs on the bacterial viability differed by 1 order of magnitude and can be related to the release of dissolved Ag(+). The release of dissolved Ag(+) can be attributed to particle size and surface area or to the fact that AgNPs are in either metallic or oxide form. Environ

Rapid Detection and Quantification of Lanthanide Ions Using High-Speed Polymerase Chain Reactions

Recently, a novel approach to a highly sensitive and quantitative detection of rare earth element (REE) ions including La3+, Eu3+ and Tb3+, by the polymerase chain reaction (PCR) technique, has been reported. The detection of REE ions is based on the catalytic nature of REE ions targeting the deoxyribonucleic acid (DNA), thus monitoring of the ions can be achieved by reading the level of intact DNA by PCR. Despite of its high sensitivity (at ppb to ppt levels), the conventional PCR-based REE detection protocol requires certain length of time (1-2 hours). In the present study, we modified the PCR-based REE detection protocols by employing the high-speed PCR, and performed the automated and rapid detection of La3+ in small-sized aqueous samples within 5min.