Adjacent Positions Research Articles

The Subjective Well-Being of Those Vulnerable to Poverty in Switzerland

This paper aims to examine the impact of being in a specific economic position, namely, being vulnerable to poverty, on people’s level of subjective well-being. Research usually focus on the top or at the bottom of the income distribution, but rarely on those in an in-between position. While the concept of poverty has been widely explored and analysed, people being vulnerable to poverty and who are struggling to maintain a certain standard of living are often neglected. This fact is probably due to the heterogeneous definition of those being vulnerable or the concept of vulnerability itself. Following the vulnerability to poverty approach, this paper estimates the effect of being in this adjacent position on the level of subjective well-being. The main hypothesis is that, people being vulnerable will report a lower level of subjective well-being compared to those in a secured position, but will be better off compared to those in poverty. Results do confirm our hypothesis, as the level of self-reported satisfaction with life is lower than the reference group for those being vulnerable to poverty, but not compared to those in poverty. However, the difference between the two groups is very small and tend to indicate similar subjective well-being. This result raise several questions and may translate how people being vulnerable to poverty feel left behind.

Unveiling the Diversity of Immunoglobulin Heavy Constant Gamma (IGHG) Gene Segments in Brazilian Populations Reveals 28 Novel Alleles and Evidence of Gene Conversion and Natural Selection.

Even though immunoglobulins are critical for immune responses and human survival, the diversity of the immunoglobulin heavy chain gene (IGH) is poorly known and mostly characterized only by serological methods. Moreover, this genomic region is not well-covered in genomic databases and genome-wide association studies due to particularities that impose technical difficulties for its analysis. Therefore, the IGH gene has never been systematically sequenced across populations. Here, we deliver an unprecedented and comprehensive characterization of the diversity of the IGHG1, IGHG2, and IGHG3 gene segments, which encode the constant region of the most abundant circulating immunoglobulins: IgG1, IgG2, and IgG3, respectively. We used Sanger sequencing to analyze 357 individuals from seven different Brazilian populations, including five Amerindian, one Japanese-descendant and one Euro-descendant population samples. We discovered 28 novel IGHG alleles and provided evidence that some of them may have been originated by gene conversion between common alleles of different gene segments. The rate of synonymous substitutions was significantly higher than the rate of the non-synonymous substitutions for IGHG1 and IGHG2 (p = 0.01 and 0.03, respectively), consistent with purifying selection. Fay and Wu's test showed significant negative values for most populations (p < 0.001), which indicates that positive selection in an adjacent position may be shaping IGHG variation by hitchhiking of variants in the vicinity, possibly the regions that encode the Ig variable regions. This study shows that the variation in the IGH gene is largely underestimated. Therefore, exploring its nucleotide diversity in populations may provide valuable information for comprehension of its evolution, its impact on diseases and vaccine research.

Screening substrate-binding positions by rolling circle amplification suggesting a binding model of Nt.BstNBI.

Nicking endonucleases (NEs) become increasingly attractive for their promising applications in isothermal amplification. Unfortunately, in comparison with their applications, their catalytic mechanism studies have relatively lagged behind due to a paucity of crystal structure information. Nt.BstNBI is one of those widely used NEs. However, many aspects of its catalytic mechanism still remained to be explored. Herein, we employed only rolling circle amplification (RCA) assay as a major analytic tool and succeeded in identifying the potential binding positions and regions of the DNA substrate based on locked nucleic acid modification, DNA duplex length of substrate, and substrate mismatch designs. Based on these data, we, for the first time, revealed that Nt.BstNBI was likely to recognize six adjacent positions of the recognition sequence (G1rt, A2rt, G3rt, A2rb, C3rb, and T4rb) in the major groove and hold three positions of the cleavage sequence (N3ct, N4ct, and N7cb) in the minor groove of DNA duplex for nicking. Moreover, this work also demonstrated the unexpected efficiency of RCA to study the macromolecular interaction for certain kind of nucleases in an easy and high-throughput way.

Letter migration errors reflect spatial pooling of orthographic information

Prior research has shown that readers may misread words by switching letters across words (e.g., the word sand in sand lane being recognized as land). These so-called letter migration errors have been observed using a divided attention paradigm whereby two words are briefly presented simultaneously, and one is postcued for identification. Letter migrations might therefore be due to a task-induced division of attention across the two words. Here, we show that a similar rate of migration errors is obtained in a flanker paradigm in which a central target word is flanked to the left and to the right by task-irrelevant flanking words. Three words were simultaneously presented for the same brief duration. Asked to type the target word postoffset, participants produced more migration errors when the migrating letter occupied the same position in the flanker and target words, with significantly fewer migrations occurring across adjacent positions, and the effect disappearing across nonadjacent positions. Our results provide further support for the hypothesis that orthographic information spanning multiple words is processed in parallel and spatially integrated (pooled) within a single channel. It is the spatial pooling of sublexical orthographic information that is thought to drive letter migration errors.

Robust Optimization for Gynecological High-Dose Rate Interstitial BrachytherapyUsing Post-Hoc Uniformity Correction

Graphical optimization (GO) is commonly used during forward planning high-dose rate (HDR) interstitial brachytherapy (IB) to conform prescription dose to high-risk clinical target volume (HRCTV) while limiting organs-at-risk (OAR) doses. However, this typically Results in variations in dwell times between adjacent dwell positions even within an interstitial catheter (Figure 1a). When using IB for locally advanced/recurrent gynecological cancers, a common fractionation approach involves 5 fractions delivered twice daily over 3 days. During this time, day-to-day variations in internal normal tissue anatomy (bowel/bladder filling) can occur. Connecting and disconnecting transfer tubes for each treatment may result in longitudinal movement of individual catheters. Above factors could impact actual dose delivered. To mitigate the impact of these variations, we seek to explore the impact of a post-hoc uniformity correction (PHUC) on the GO plan and report an initial clinical experience with using this robust optimized (RO) approach.

Multi-Constrained Optimization Method of Line Segment Extraction Based on Multi-Scale Image Space

Image-based line segment extraction plays an important role in a wide range of applications. Traditional line segment extraction algorithms focus on the accuracy and efficiency, without considering the integrity. Serious line segmentation fracture problems caused by image quality will result in poor subsequent applications. To solve this problem, a multi-constrained line segment extraction method, based on multi-scale image space, is presented. Firstly, using Gaussian down-sampling with a classical line segment detection method, a multi-scale image space is constructed to extract line segments in each image scale and all line segments are projected onto the original image. Then, a new line segment optimization and purification strategy is proposed with the horizontal and vertical distances and angle geometric constraint relationships between line segments to merge fracture line segments and delete redundant line segments. Finally, line segments with adjacent positions are optimized using the grayscale constraint relationship, based on normalized cross-correlation similarity criterion for realizing the second optimization of fracture line segments. Compared with mainstream line segment detector and edge drawing lines methods, experimental results (i.e., indoor, outdoor, and aerial images) indicate the validity and superiority of our proposed methods which can extract longer and more complete line segments.

Human Resilience and the Gut Microbiome

ObjectiveThis project evaluated the relationship of gut microbiome composition of first year medical students and stress resilience over a period of 4 months. Our objective was to identify gut microbiome characteristics of individuals that showed long term stress resilience.MethodsStudents were voluntarily recruited and screened for lifestyle and environmental factors. Their degree of psychologic stress at 3 timepoints during the first semester was measured with Cohen's perceived stress scale and PHQ‐9 depression scores. Fecal samples were collected at the same time using uBiome home kits at participant convenience. Samples were processed by uBiome and amplified for the 16s V4 gene. Stress and depression scores were normalized and summed to produce a psychologic index score. These scores were used to identify what microbiome characteristics may be correlated to stress resiliency of susceptibility. Metagenomic workup was performed using QIIME, MetaComet, and R Studio.Summary of resultsAcross phyla present in 100% of samples, none were independently correlated with psychologic scores using a linear model while Bacteroidete:Firmicute ratio showed a significant negative linear correlation with the psychologic index (Pearon's, p=0.05, R=−0.24). Phylogenetic assembly of participants by microbiome relatedness found that 100% of subjects who were resilient to stress across all timepoints (n=8) were phylogenetically clustered in adjacent positions, showing a high degree of temporal stability. Of participants who were not durably resilient to stress, only 62% of participants (n=8) showed microbiomes that were phylogenetically related across the same 4 month period. We identified 2,102 Operational Taxonomic Units (OTUs) which were unique to the durable resilience group and 94 OTUs which were unique to the susceptible group. Of the 4,794 observed OTUs, 6.1% (n=294) were significantly different between groups by Kruskal‐Wallis before post‐test adjustment.ConclusionFindings of a correlation between an index accounting for stress and depression and the abundance of Bacteroidetes: Firmicutes, and a relationship between durable resiliency and microbiome stability support that the gut microbiome may play an important role in stress resilience at a time scale of 4 months. More research is indicated in this field to identify microbiome characteristics which are responsible for stress resilience. These may include the presence or absence of specific taxa or ratios between taxa, such as the Bacteroidete:Firmicute ratio. Eventually, a better understanding of the role of the gut microbiome in stress resilience may someday create opportunities to help those with conditions which are characterized by low stress resilience when faced with new challenges. We hope someday that exploration of the microbiome will produce actionable, clinically relevant opportunities.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Performance comparison of aperture-less and confocal infrared microscopes

We compared hyperspectral infrared raster maps and images for contrast, definition and resolution of the same samples recorded with a confocal microscope coupled with a synchrotron radiation source vs a Focal Plane Array (FPA) detector equipped microscope. Biological samples (hair and skin sections) and astrophysics samples (meteoritic grains) were used. The samples presented are a few microns in size, such as embedded particles, a single unique cell or thin layer. Our results show that the actual spatial resolution and contrast of FPA images were lower than spectral maps from the confocal microscope. The FPA microscope also produced measurements that lacked accuracy: size of sample features and peak intensity were inaccurately estimated. More surprisingly, the intensity of absorption peaks in the FPA images was lower than the intensity measured from the same sample with a confocal microscope. Our measurements underlined the complementarity of FPA and confocal microscopes. FPA can be used to quickly measure the overall composition of a sample and detect the distribution of its components, but may fail measuring the exact chemical composition of the small features and may not detect weak spectral differences between adjacent positions. The averaging effect of aperture-less systems not only affects image resolution but also lowers their spectral accuracy. Confocal microscopes are inherently slower but give a more accurate measurement of the local composition at the diffraction limit.

Details preserved brightness equalization algorithm for non-uniform illumination images

In order to overcome the limitation of current image enhancement algorithms for non-uniform illumination images, a brightness equalization algorithm is proposed to preserve the detail information in low illumination region and normal illumination region at the same time. The algorithm uses the adjacent frequency and position of pixels to generate illumination filter, so it can effectively separate illumination information and reflection information with details. The illumination threshold is used to divide different illumination areas to compensate for low illumination brightness, so as to balance the image brightness. The experimental results show that compared with the classical naturalness preserved enhancement algorithm (NPEA), the average peak signal to noise ratio of the image increases by 15.4%, the average enhancement degree increases by 245.0%, and the average brightness step difference decreases by 25.4%. The results of the proposed algorithm can maintain the details of different illumination areas while balancing the brightness and obtain a better visual effect.

A novel quick and highly selective “turn-on” fluorescent probe for Hg2+ and its application

In the present work, we reported the simple synthetic strategy of fluorescent probe BAA. In order to increase the binding ability and selectivity of the probe for Hg2+, an alkynyl group was introduced on the adjacent position of the azo group of the probe. The molecular structure of BAA was characterized by 1H NMR, 13C NMR, IR, and MALDI-TOF. Spectrum analysis indicated that BAA exhibited high selective turn-on fluorescence signal and rapid response (about 10 s) to Hg2+. The selectivity can also be visualized under UV light, the BAA shows green fluorescence emission only in the presence of Hg2+. The stoichiometric ratio (1:1) between the probe and Hg2+ could be obtained by the Job-plot and ESI-MS analysis, and was confirmed by quantum chemical calculations. The detection limit of Hg2+ was 1.30 × 10−7 M in aqueous media. We have demonstrated the suggested probe can detect Hg2+ in lake water samples with satisfying results. Moreover, it exhibits excellent membrane permeability and has been successfully used for detection of Hg2+ in MCF-7 living cells by confocal fluorescence imaging. The explored facile “turn-on” Hg2+ fluorescent probe here may have the further potential applications in environmental testing, biomedicine and food analysis.

Crystal structure and Hirshfeld surface analysis of dimethyl (1R*,3aS*,3a1 R*,6aS*,9R*,9aS*)-3a1,5,6,9a-tetra-hydro-1H,4H,9H-1,3a:6a,9-di-epoxy-phenalene-2,3-di-carboxyl-ate.

The title di-epoxy-phenalene derivative, C17H18O6, comprises a fused cyclic system containing four five-membered rings (two di-hydro-furan and two tetra-hydro-furan) and one six-membered ring (cyclo-hexa-ne). The five-membered di-hydro-furan and tetra-hydro-furan rings adopt envelope conformations, and the six-membered cyclo-hexane ring adopts a distorted chair conformation. Two methyl carboxyl-ate groups occupy adjacent positions (2- and 3-) on a tetra-hydro-furan ring. In the crystal, two pairs of C-H⋯O hydrogen bonds link the mol-ecules to form inversion dimers, enclosing two R 2 2(6) ring motifs, that stack along the a-axis direction and are arranged in layers parallel to the bc plane.

T1 Measuring Burn Scar Contracture: Challenging the Standard

Standard goniometry is the most commonly used method of assessing range of motion (ROM) in patients with burn scar contracture. However, standard goniometry disregards the cutaneous biomechanical influence between adjacent joint positions and skin (or scar) pliability to accommodate motion. Given that natural skin is a single, continuous piece of tissue enveloping the entire body without joints, the appropriateness of standard goniometry to quantify motion when burn scars or other integumentary impairments are the source of limitation, is called into question. We conducted a prospective, multi-center, comparative study investigating the difference between two goniometric protocols for measuring ROM outcome in burn survivors: 1) standard goniometry - based on arthrokinematics and 2) revised goniometry - based on principles of cutaneokinematics and functional positions. Maximal active ROM was measured for 11 motions, three times in each position in random order. Data were summarized using means and standard deviations and analyzed using a mixed model ANOVA with each subject representing a random effect in the model. Pearson’s Correlations were performed between the severity of limitation and the percentage of scar involvement. Data were collected for 174 joints from 66 subjects at seven different burn centers, resulting in a total of 1044 goniometric measurements for comparison. ROM findings using the revised goniometric protocol demonstrated significantly more limitation in motion 38.8 %±15.2% than the standard goniometric protocol 32.1% ±13.4% (p<.0001). Individual analyses of the motions likewise, showed significantly more limitation with the revised methods compared to the standard methods for 9/11 motions. Pearson’s correlation showed a significant positive correlation between the percentage of area affected by scarring and ROM outcome with revised goniometry (R2=.05, p=.0008) and the Δ between the revised and standard protocols (R2=.04, p=.0025) but no correlation was found with standard goniometry (R2=.015, p=.065). These findings support the notion that standard goniometry underestimates the ROM impairment for individuals whose motion is limited by burn scars. Due to the high frequency of movement related problems that burn survivors experience, ROM is a foundational outcome measure. It is used as a marker of recovery, influences function, affects quality of life and contributes to the decision of resource allocation during recovery. Therefore, having measurement methods that consider the unique characteristics of skin impairment is an important priority for both clinical reporting and future research in burn care. Clinical change in fundamental methods of measuring ROM after burn injury.

8-Oxo-guanine DNA damage induces transcription errors by escaping two distinct fidelity control checkpoints of RNA polymerase II

RNA polymerase II (Pol II) has an intrinsic fidelity control mechanism to maintain faithful genetic information transfer during transcription. 8-Oxo-guanine (8OG), a commonly occurring damaged guanine base, promotes misincorporation of adenine into the RNA strand. Recent structural work has shown that adenine can pair with the syn conformation of 8OG directly upstream of the Pol II active site. However, it remains unknown how 8OG is accommodated in the active site as a template base for the incoming ATP. Here, we used molecular dynamics (MD) simulations to investigate two consecutive steps that may contribute to the adenine misincorporation by Pol II. First, the mismatch is located in the active site, contributing to initial incorporation of adenine. Second, the mismatch is in the adjacent upstream position, contributing to extension from the mismatched bp. These results are supported by an in vitro transcription assay, confirming that 8OG can induce adenine misincorporation. Our simulations further suggest that 8OG forms a stable bp with the mismatched adenine in both the active site and the adjacent upstream position. This stability predominantly originates from hydrogen bonding between the mismatched adenine and 8OG in a noncanonical syn conformation. Interestingly, we also found that an unstable bp present directly upstream of the active site, such as adenine paired with 8OG in the canonical anti conformation, largely disrupts the stability of the active site. Our findings have uncovered two main factors contributing to how 8OG induces transcriptional errors and escapes Pol II transcriptional fidelity control checkpoints.

The role of control processes in temporal and semantic contiguity.

Atkinson and Shiffrin (1968) argued that performance on any memory task reflects the combined influence of both the fixed structure of the memory system and control processes tailored to the specific task. We investigated the role of control processes in governing the temporal contiguity and semantic contiguity effects in free recall-tendencies to organize recall based on proximity in the study list and pre-existing semantic associations. Subjects studied lists that contained four "clusters", each composed of four semantically associated words but presented in random order such that associates were not in adjacent serial positions. Subjects were given either standard free-recall instructions, instructions to focus on order-based associations (i.e., the original order of presentation), or meaning-based associations (i.e., pre-existing semantic relationships). Replicating previous work, lists with strong semantic relationships resulted in a reduced overall temporal contiguity effect when recalled under standard free-recall instructions. However, under meaning-based recall instructions, the temporal contiguity effect was nearly eliminated. Detailed analyses of within-cluster transitions and an order reconstruction task revealed that temporal information was encoded, but control processes prevented it from dominating memory search. These results point to a need for more empirical work exploring how control processes change recall dynamics and for more theoretical work modeling the computational basis of these processes.

Multislice motion modeling for MRI-guided radiotherapy gating.

On-board magnetic resonance imaging (MRI) greatly enhances real-time target tracking capability during radiotherapy treatments. However, multislice and volumetric MRI techniques are frame rate limited and introduce unacceptable latency between the target moving out of position and the beam being turned off. We present a technique to estimate continuous volumetric tissue motion using motion models built from a repeated acquisition of a stack of MR slices. Applications including multislice target visualization and out-of-slice motion estimation during MRI-guided radiotherapy are demonstrated. Eight healthy volunteer studies were performed using a 0.35T MRI-guided radiotherapy system. Images were acquired at three frames per second in an interleaved fashion across ten adjacent sagittal slice positions covering 4.5cm using a balanced steady-state-free precession sequence. A previously published five-dimensional (5D) linear motion model used for MRI-guided radiotherapy gating was extended to include multiple slices. This model utilizes an external respiratory bellows signal recorded during imaging to simultaneously estimate motion across all imaged slices. For comparison to an image-based approach, the manifold learning technique local linear embedding (LLE) was used to derive a respiratory surrogate for motion modeling. Manifolds for every slice were aligned during LLE in a group-wise fashion, enabling motion estimation outside the current imaged slice using a motion model, a process which we denote as mSGA. Additionally, a method is developed to evaluate out-of-slice motion estimates. The multislice motion model was evaluated in a single slice with each newly acquired image using a leave-one-out approach. Model-generated gating decision accuracy and beam-on positive predictive value (PPV) are reported along with the median and 95th percentile distance between model and ground truth target centroids. The average model gating decision accuracy and PPV across all volunteer studies was 93.7% and 92.8% using the 5D model, and 96.8% and 96.1% using the mSGA model, respectively. The median and 95th percentile distance between model and ground truth target centroids was 0.91 and 2.90mm, respectively, using the 5D model and 0.58 and 1.49mm using the mSGA model, averaged over all eight subjects. The mSGA motion model provided a statistically significant improvement across all evaluation metrics compared to the external surrogate-based 5D model. The proposed techniques for out-of-slice target motion estimation demonstrated accuracy likely sufficient for clinical use. Results indicate the mSGA model may provide higher accuracy, however, the external surrogate-based model allows for unbiased invivo accuracy evaluation.

A new benzimidazole‐based selective and sensitive ‘on–off’ fluorescence chemosensor for Cu2+ ions and application in cellular bioimaging

Two new twinborn benzimidazole derivates (L and A), which bonded pyridine via the ester space on the opposite and adjacent positions of the benzene ring of benzimidazole respectively, were designed and synthesized. Compound L displayed fluorescence quenching response only towards copper(II) ions (Cu2+ ) in acetonitrile solution with high selectivity and sensitivity. However, compound A presented 'on-off' fluorescence response towards a wide range of metal ions to different degrees and did not have selectivity. Furthermore, compound L formed a 1:1 complex with Cu2+ and the binding constant between sensor L and Cu2+ was high at 6.02×104 M-1 . Job's plot, mass spectra, IR spectra, 1 H-NMR titration and density functional theory (DFT) calculations demonstrated the formation of a 1:1 complex between L and Cu2+ . Chemosensor L displayed a low limit of detection (3.05×10-6 M) and fast response time (15s) to Cu2+ . The Stern-Volmer analysis illustrated that the fluorescence quenching agreed with the static quenching mode. In addition, the obvious difference of L within HepG2 cells in the presence and absence of Cu2+ indicated L had the recognition capability for Cu2+ in living cells.

Calculation of Deviations of Shape, Size and Location of Flat Surfaces

The development of computerization allows the development of mathematical models of physical processes with different methods of blade machining of machine parts. Modern programmable CNC machines have the ability to produce parts in an automated cycle, ensuring the requirements of the drawing. Control of the quality of processing of the main flat surfaces, which are technological and Assembly bases, should be considered in more detail. Their accuracy in accordance with the standards is determined by the shape deviations from the adjacent planes, size and relative position. The standards have instructions on how to create a virtual adjacent plane using adjustable supports and further scan the ordinates of its individual points to calculate the deviation of the form. To quantify the deviations of shape, size and location is not enough to have a field f, the vectors of which are defined from the geometric plane, given the nominal size, it is necessary to establish a base for their reference. The question of establishing bases for reference is not only of fundamental importance, since different bases can be obtained different values of deviations. The paper proposes a mathematical model for determining the named parameters of accuracy from the middle planes, which are determined by the calculated vectors at specific points of the treated surface when processing batches of blanks on milling machines face milling.

Automatic Detection of Single Ripe Tomato on Plant Combining Faster R-CNN and Intuitionistic Fuzzy Set

Fast and accurate detection of ripe tomatoes on plant, which replaces manual labor with a robotic vision-based harvesting system, is a challenging task. Tomatoes in adjacent positions are easily mistaken as a single tomato by image recognition methods. In this study, a ripe tomato detection method that combines deep learning with edge contour detection is proposed. Our approach efficiently separates target tomatoes from overlapping tomatoes to detect individual fruits. This approach yields several improvements. First, deep learning requires less time and extracts deeper features than traditional methods for assessing candidate ripe tomato regions. Second, we use Gaussian density function of H and S in the HSV color space to help segment tomato regions from the background, followed by erosion and dilation on the tomato body to separate adjacent tomatoes and remove peripheral subpixels from all detected ripe tomatoes. Third, an adaptive threshold intuitionistic fuzzy set (IFS) method was developed to identify the tomato's edge, and it performs well in detecting blurred edges in overlapping regions. To improve the efficiency and stability of edge detection under natural conditions, we adopted an illumination adjustment algorithm for the tomato image before edge detection. As samples, we collected images showing tomatoes that were separated, adjacent, overlapped, and even shaded by leaves. The widths and heights of these tomato samples were calculated and analyzed to evaluate the detection performance of the proposed method. The root mean square error (RMSE) results for tomato width and height using the proposed method are 2.996 pixels and 3.306 pixels, respectively. The mean relative error percent (MRE%) values for horizontal and vertical center position shift are 0.261% and 1.179%, respectively. These results demonstrate that the proposed method improves tomato detection accuracy and that it can be further applied in the harvesting process of agricultural robots.

The extraordinary richness of the reaction between diazomethane and tetracyanoethylene: can computational calculations shed light on old papers?

In the quest of the structure of the intermediate between Δ1- and Δ2-pyrazolines, the reactivity of these molecules tetrasubstituted by cyano groups in adjacent positions (3,3,4,4 or 4,4,5,5) has been explored in their neutral and protonated forms.

Learning to Improve WLAN Indoor Positioning Accuracy Based on DBSCAN-KRF Algorithm From RSS Fingerprint Data

WLAN-based indoor positioning algorithm has the characteristics of simple layout and low price, and it has gradually become a hotspot in both academia and industry. However, due to the poor stability of Wi-Fi signals, received signal strength (RSS) fingerprints of some adjacent reference positions are difficult to evaluate similarity when utilizing traditional distance-based calculation methods. By clustering these RSS fingerprints into one region, the commonly utilized KNN algorithm in the past cannot achieve accurate positioning in the region. For this, we introduce a concept of the insensitive region of the RSS fingerprint and a new algorithm named DBSCAN-KRF. This algorithm can delete noise sample and detect insensitive region, then, different methods are selected to achieve indoor positioning by judging the region of the estimated fingerprint sample, the KNN algorithm is selected when the region is sensitive, and random forest algorithm is selected when the region is insensitive. The experimental results show that the DBSCAN-KRF algorithm is superior while compared with other alternative indoor positioning algorithms.