Parallel Fourier ptychographic microscopy reconstruction method based on FPGA.

Fourier ptychographic microscopy (FPM) can bypass the limitation of spatial bandwidth product to get images with large field-of-view and high resolution. The complicated sequential iterative calculation in the FPM reconstruction process reduces the reconstruction efficiency of the FPM. Therefore, we propose a parallel FPM reconstruction method based on field programmable gate array (FPGA) to accelerate the FPM reconstruction process. Using this method, multiple sub-regions in the Fourier domain can be computed in parallel and we customize a dedicated high-performance computational architecture for this approach. We deploy 4 FPM reconstruct computing architectures with a parallelism of 4 in a FPGA to compute the FPM reconstruction process, achieving the speed nearly 180 times faster than traditional methods. The proposed method provides a new perspective of parallel computing for FPM reconstruction.

High-performance heterogeneous FPGA data-flow architecture for Fourier ptychographic microscopy.

Fourier ptychographic microscopy (FPM) is a recently developed computational imaging technique that can achieve both high-resolution and a wide field-of-view via a sequence of low-resolution images. FPM is a complex iterative process, and it is difficult to meet the needs of rapid reconstruction imaging with the conventional FPM deployed on general purpose processors. In this paper, we propose a high-performance heterogeneous field-programmable gate array (FPGA) architecture based on the principle of full pipeline and the data-flow structure for the iterative reconstruction procedure of FPM. By optimizing the architecture network at gate-level logic circuits, the running time of the FPGA-based FPM reconstruction procedure is nearly 20 times faster than conventional methods. Our proposed architecture can be used to develop FPM imaging equipment that meets resource and performance requirements.

Evaluating the expression of tumorigenic long noncoding RNAs in circulating exosomes isolated from non-small-cell lung cancer patients.

Aim: To evaluate the correlation of long noncoding RNAs (lncRNAs) expression in circulating exosomes and the cancerous and noncancerous tissues in patients with non-small-cell lung carcinoma. Methods: The relative expression of the four lncRNAs including LUADT1, MALAT1, NEAT1 and MIAT between tumor tissue, adjacent noncancerous tissues and circulating exosomes were evaluated by quantitative reverse transcription PCR. Results & conclusion: The relative expression of the lncRNAs, including LUADT1, MALAT1 and NEAT1, was upregulated and MIAT was downregulated in tumor tissue compared with noncancerous tissue samples. The expression of lncRNAs in circulating exosomes was not significantly different from cancerous tissue. Our results indicate that the studied exosomal lncRNAs have a good potential to be further evaluated as prognostic/diagnostic biomarkers in patients with non-small-cell lung cancer.

Dither removing Fourier ptychographic microscope based on a two-axis rotation stage.

SIGNIFICANCE: Large space-bandwidth product is highly desirable in many biomedical imaging. Fourier ptychographic microscopy (FPM) is a computational imaging technique that can significantly increase the space-bandwidth product of a standard microscope. The illuminator of a Fourier ptychographic microscope is not flexible at present, and it is inconvenient to meet different imaging needs. AIM: An illuminator based on a two-axis motorized rotation stage was presented to provide a more flexible illuminating way with the goal of meeting different imaging needs. APPROACH: The illuminator adopts a concentric illuminating method to provide coherent illumination in any direction on the sample plane. The sampling pattern can be freely designed and changed according to the parameters of the imaging system. A dither removing algorithm was proposed to remove the potential dither influence introduced in the image acquisition process. RESULTS: The illuminator could be conveniently integrated into different imaging systems. The feasibility and flexibility were demonstrated by applying it to imaging systems with numerical aperture of 0.045 and 0.01. The resolution gain is about 4- and 13-fold, respectively. The effectiveness of the dither removing algorithm was validated in both simulation and experiment. CONCLUSIONS: A more flexible illuminator for FPM was presented to meet different imaging needs. A dither removing algorithm was proposed to remove dither influence.

Automated Embryo Manipulation and Rotation via Robotic nDEP-Tweezers.

Embryo manipulation is a fundamental task in assisted reproductive technology (ART). Nevertheless, conventional pick-place techniques often require proper alignment to avoid causing damage to the embryo and further, the tools have limited capability to orient the embryo being handled. OBJECTIVE: This paper presents a novel and non-invasive technique that can easily manipulate mouse embryos on a polyvinyl chloride (PVC) Petri dish. METHODS: An inverted microchip with quadrupole electrodes was attached to a micromanipulator to become a robotic dielectrophoresis (DEP) tweezers, and a motorized platform provided additional mobility to the embryos lying on a Petri dish. Vision-based algorithms were developed to evaluate relevant information of the embryos from the image, and to provide feedback signals for precise position and orientation control of the embryo. RESULTS: A series of experiments was conducted to examine the system performance, and the embryo can be successfully manipulated to a specified location with the desired orientation for subsequent processing. CONCLUSION: This system offers a non-contact, low cost, and flexible method for rapid cell handling. SIGNIFICANCE: As the DEP tweezers can grasp the embryo without the need for precise alignment, the overall time required to process a large number of embryos can be shortened.

Microchip System for Patterning Cells on Different Substrates via Negative Dielectrophoresis.

Seeding cells on a planar substrate is the first step to construct artificial tissues in vitro. Cells should be organized into a pattern similar to native tissues and cultured on a favorable substrate to facilitate desirable tissue ingrowth. In this study, a microchip system is designed and fabricated to form cells into a specific pattern on different substrates. The system consists of a microchip with a dot-electrode array for cell trapping and patterning and two motorized platforms for providing relative motions between the microchip and the substrate. AC voltage is supplied to the selected electrodes by using a programmable micro control unit to control relays connected to the dot-electrodes. Nonuniform electric fields for cell manipulation are formed via negative dielectrophoresis (n-DEP). Experiments were conducted to create different patterns by using yeast cells. The effects of different experimental parameters and material properties on the patterning efficiency were evaluated and analyzed. Mechanisms to remove abundant cells surrounding the constructed patterns were also examined. Results show that the microchip system could successfully create cell patterns on different substrates. The use of calcium chloride (CaCl 2) enhanced the cell adhesiveness on the substrate. The proposed n-DEP patterning technique offers a new method for constructing artificial tissues with high flexibility on cell patterning and selecting substrate to suit application needs.

Hyperspectral imaging using the single-pixel Fourier transform technique.

Hyperspectral imaging technology is playing an increasingly important role in the fields of food analysis, medicine and biotechnology. To improve the speed of operation and increase the light throughput in a compact equipment structure, a Fourier transform hyperspectral imaging system based on a single-pixel technique is proposed in this study. Compared with current imaging spectrometry approaches, the proposed system has a wider spectral range (400-1100 nm), a better spectral resolution (1 nm) and requires fewer measurement data (a sample rate of 6.25%). The performance of this system was verified by its application to the non-destructive testing of potatoes.

Interpersonal-psychological theory and parental bonding predict suicidal ideation among soldiers in Taiwan.

INTRODUCTION: Suicide is an important issue among military personnel, who have higher suicide rates compared with the general population. The interpersonal-psychological theory of suicide (IPTS) might provide an empirical explanation of this phenomenon, and parental bonding influences social adjustment and suicide. To investigate the relevance of IPTS and parental bonding for suicide among Taiwanese soldiers, a case-control study was conducted. METHODS: Using a suicide-reporting system in a teaching general hospital in Southern Taiwan, 226 at-risk maladjusted soldiers and 229 well-adjusted controls were enrolled. We collected basic information, and participants answered four IPTS-based questions. Suicide risk was assessed using the Brief Symptom Rating Scale item 6. A four-factor model of the Parental Bonding Instrument assessed parental bonding. All participants were interviewed using the Mini International Neuropsychiatric Interview for primary screening and to recheck the accuracy of the Brief Symptom Rating Scale item 6 score. RESULTS: A parsimonious model obtained by regression analysis of risk factors indicated that poor academic performance, conduct-related issues in childhood, and exposure to life-threatening situations are risk factors for suicide intention. Maladjusted suicidal soldiers showed a sense of thwarted belongingness (ß = 0.145; P < 0.001), higher perceived burdensomeness (ß = 0.311; P < 0.001), less fear of death (ß = 0.124; P < 0.05), lower paternal autonomy (ß = -0.122; P < 0.05), and higher maternal indifference (ß = 0.162; P < 0.0001). DISCUSSION: Interpersonal-psychological theory of suicide, accompanied by an assessment of parental bonding, could be used for assessing suicide risk and preventing suicide attempts.

Interpersonal-Psychological Theory, Alexithymia, and Personality Predict Suicide Ideation among Maladjusted Soldiers in Taiwan.

This case-control study enrolled 226 maladjusted soldiers and 229 controls to investigate the impact of the interpersonal-psychological theory of suicide, alexithymia, personality, and childhood trauma on suicide risk among Taiwanese soldiers. Assessments included the Toronto Alexithymia Scale, Eysenck Personality Inventory, Mini-International Neuropsychiatric Interview, and Brief Symptom Rating Scale. In addition to thwarted belongingness and perceived burdensomeness, other risks included less extraversion with higher neuroticism, higher alexithymia, poor academic performance, domestic violence, and life-threatening events. Our study demonstrates the interaction of the interpersonal-psychological theory and other suicide risk factors in Taiwanese soldiers.

Assessments of Drought Impacts on Vegetation in China with the Optimal Time Scales of the Climatic Drought Index.

Drought is expected to increase in frequency and severity due to global warming, and its impacts on vegetation are typically extensively evaluated with climatic drought indices, such as multi-scalar Standardized Precipitation Evapotranspiration Index (SPEI). We analyzed the covariation between the SPEIs of various time scales and the anomalies of the normalized difference vegetation index (NDVI), from which the vegetation type-related optimal time scales were retrieved. The results indicated that the optimal time scales of needle-leaved forest, broadleaf forest and shrubland were between 10 and 12 months, which were considerably longer than the grassland, meadow and cultivated vegetation ones (2 to 4 months). When the optimal vegetation type-related time scales were used, the SPEI could better reflect the vegetation's responses to water conditions, with the correlation coefficients between SPEIs and NDVI anomalies increased by 5.88% to 28.4%. We investigated the spatio-temporal characteristics of drought and quantified the different responses of vegetation growth to drought during the growing season (April-October). The results revealed that the frequency of drought has increased in the 21st century with the drying trend occurring in most of China. These results are useful for ecological assessments and adapting management steps to mitigate the impact of drought on vegetation. They are helpful to employ water resources more efficiently and reduce potential damage to human health caused by water shortages.

Time-lag effects of global vegetation responses to climate change.

Climate conditions significantly affect vegetation growth in terrestrial ecosystems. Due to the spatial heterogeneity of ecosystems, the vegetation responses to climate vary considerably with the diverse spatial patterns and the time-lag effects, which are the most important mechanism of climate-vegetation interactive effects. Extensive studies focused on large-scale vegetation-climate interactions use the simultaneous meteorological and vegetation indicators to develop models; however, the time-lag effects are less considered, which tends to increase uncertainty. In this study, we aim to quantitatively determine the time-lag effects of global vegetation responses to different climatic factors using the GIMMS3g NDVI time series and the CRU temperature, precipitation, and solar radiation datasets. First, this study analyzed the time-lag effects of global vegetation responses to different climatic factors. Then, a multiple linear regression model and partial correlation model were established to statistically analyze the roles of different climatic factors on vegetation responses, from which the primary climate-driving factors for different vegetation types were determined. The results showed that (i) both the time-lag effects of the vegetation responses and the major climate-driving factors that significantly affect vegetation growth varied significantly at the global scale, which was related to the diverse vegetation and climate characteristics; (ii) regarding the time-lag effects, the climatic factors explained 64% variation of the global vegetation growth, which was 11% relatively higher than the model ignoring the time-lag effects; (iii) for the area with a significant change trend (for the period 1982-2008) in the global GIMMS3g NDVI (P < 0.05), the primary driving factor was temperature; and (iv) at the regional scale, the variation in vegetation growth was also related to human activities and natural disturbances. Considering the time-lag effects is quite important for better predicting and evaluating the vegetation dynamics under the background of global climate change.

Chinese narcotics trafficking: a preliminary report.

Questions of existence of the "China Route" for drug smuggling and trafficking have been important in the literature. The profile of the offenders, particularly whether they are primarily members of traditional criminal organization, is a hotly debated issue. Much qualitative evidence has been collected and it provides important insights into these questions. However, little quantitative data has ever been collected and analyzed to provide a broader picture of these issues. The present study involves the systematical collection of data from court sentencing files from seven high courts whose jurisdictions cover the China Route. The findings provide valuable information that sheds light on the debated questions. Some evidence consistent with the China Route arguments is found. No evidence supports the idea that traditional organized criminal syndicates are behind most offenses. Logistic regression results reveal interesting associations between offender characteristics and types of offenses.

The role of criminal justice system in treating drug abusers: the Chinese experience.

This study explores the role of China's criminal justice system in treating drug abusers and provides a preliminary assessment of the mandatory treatment centers administered by police and reeducation-through-labor camps managed by correction agencies in China. The exploration and assessment are conducted using data collected from recent surveys of drug users in several mandatory treatment centers and a reeducation-through-labor camp in a large city of China in 2009. The data reveal that the treatment involvement levels of drug users in these mandatory treatment centers and reeducation-through-labor camps varied and their perceptions of the treatments they had received for their recovery seem fairly positive. The implication of these findings was discussed in the context of Chinese social and legal tradition.

Drug problems in contemporary China: a profile of Chinese drug users in a metropolitan area.

BACKGROUND: Drug problems are reemerging in China since the nation implemented economic reform and an "open door" policy in the early 1980s. This is causing both national and international concern. However, knowledge and understanding of the Chinese drug problem is fairly limited because of the nation's unique social and political history. In response to this shortage of information, our study presents a profile of Chinese drug users. METHODS: Data were collected from a survey of drug users attending mandatory treatment centres in a large city in 2009. We present a demographic profile of the drug users, describe their patterns of drug use, their access to drugs and their history of drug treatment. RESULTS: Chinese drug users, like those from the U.S., are likely to be unemployed and have a low level of education. However, they are more likely than those in the U.S. to use heroin, Bingdu (methamphetamine) and Maguo (a derivative of methamphetamine), and they pay less for their drugs. CONCLUSION: This profile of drug users is informative and valuable for drug prevention, intervention, and treatment in the Chinese setting because knowing and understanding the drug population is essential for effective control.

Drug problems in China: recent trends, countermeasures, and challenges.

Drug crime in China is on an overall rising trend. Major drug crime cases are becoming more common, the types of drugs being trafficked are more diverse, and the smuggling and trafficking of drugs into the country and the smuggling of precursor chemicals out of the country have formed a bidirectional cycle. Drug crimes in China have also begun to show a conspicuous trend of internationalization. China's main countermeasures against drug crimes have been to pass new laws and regulations against drugs, to increase the efforts to eradicate cultivation, to establish and expand "drug-free communities" programs, and to strengthen international cooperation in antidrug campaigns. The existing problems demand prompt solutions, which include a shortage of funding and lack of accurate knowledge about prevalence of drug abuse and related data for scientifically studying the drug problems.