Size Shrinkage Research Articles

LSOP: Layer-Scaled One-shot Pruning

Neural network pruning is a technique that removes unnecessary weight parameters from a network to decrease its memory and computational requirements. Many different pruning techniques have been proposed to reduce networks with over 90% shrinkage in size while minimizing accuracy loss. This paper aims to establish a framework that can generalize the mechanism among various pruning techniques, which can be used to guide users to design better deep pruning methods in the future. With some basic concepts and findings from data matrix approximation, the framework can explain the success of the state-of-the-art methods as well as a more generalized pruning design (Layer-Scaled One-shot Pruning, LSOP) proposed in this work. After pruning with different algorithms and measuring their accuracies, the researcher also found that those methods or algorithms aligned with the proposed framework were more accurate at sparser networks (density < 10%) than the methods that did not. This suggests that future research into neural network pruning can focus on the proposed framework, which has the potential to accelerate the development of pruning technology and adoption of more efficient neural networks.
 
 The LSOP framework’s capability to explain strong pruning performances implies that polynomial decay and Low-Rank Matrix Approximation techniques from the field of data science can provide support for neural network pruning.

Image-based model for dynamic apparent gas permeability in Organic-rich shales

Current shale gas apparent permeability models often fail to integrate morphological properties of multiple storage spaces and various transport mechanisms. To deal with this, we propose a comprehensive model for estimating the dynamic apparent gas permeability (DAGP) during depressurization based on a representative model. First, dual fractal characteristics of organic matter (OM) particles and inorganic matter (IOM)/OM pores along with morphological information of OM particles from scanning electron microscope (SEM) images are considered to establish the representative model conditioned to a total organic carbon (TOC) content. Next, multiple transport mechanisms and a pore size change due to a poromechanical response and desorption-induced volumetric strain are incorporated in the DAGP calculation. Results reveal that the controlling factor of the DAGP comes from pore size shrinkage owing to a poromechanical response to gas transport mechanisms during depressurization at a high Young’s modulus, while the DAGP is totally controlled by a poromechanical response at a low Young’s modulus. The critical TOC content is determined to be about 5% at which the influence of the degree of OM pore development can be neglected. This work provides a practical method to estimate the DAGP from both geostatistical and petrophysical perspectives, which effectively decreases the uncertainty during productivity prediction in shale gas reservoirs and other unconventional reservoirs.

Low-threshold all-optical nonlinear activation function based on a Ge/Si hybrid structure in a microring resonator

Optical nonlinear activation function is an indispensable part of the optical neural network. While linear matrix computation has thrived in an integrated optical neural network, there are many challenges for nonlinear activation function on a chip such as large latency, high power consumption and high threshold. Here, we demonstrate that Ge/Si hybrid structure would be a qualified candidate owing to its property of CMOS-compatibility, low nonlinear threshold and compact footprint. Thanks to the strong thermal-optic effect of germanium in conjunction with micro-ring resonator, we experimentally demonstrate three different types of nonlinear function (Radial basis, Relu and ELU functions) with a lowest threshold of 0.74 mW among our measured nonlinear functions and they can work well with a repetition rate below 100 kHz. Simultaneous size shrinkage of germanium and resonance constraint inside germanium is proposed to speed up response time. Furthermore, we apply our measured nonlinear activation function to the task of classification of MNIST handwritten digit image dataset and improve the test accuracy from 91.8% to 94.8% with feedforward full-connected neural network containing three hidden layers. It proves that our scheme has potential in the future optical neural network.

Age-related neuronal damage by advanced glycation end products through altered proteostasis

Aging is a main risk factor for many diseases including neurodegenerative disorders. Numerous theories and mechanisms including accumulation of advanced glycation end products (AGEs) have been put forward in explaining brain aging. However, a focused study on the status of AGEs in the brain during progressive aging in connection with interrelated cellular processes like ubiquitin-proteasome system (UPS), unfolded protein response, autophagy-lysosome system and apoptosis is lacking. In this study, we investigated the levels of AGEs in the brain of 5-, 10-, 15- and 20-months old WNIN rats. Endoplasmic reticulum (ER) stress response, UPS components, autophagy flux, neurotrophic and presynaptic markers along with cell death markers were analyzed by immunoblotting. The neuronal architecture was analyzed by H&E and Nissl staining. The results demonstrated progressive accumulation of AGEs in the brain during aging. Adaptive ER stress response was observed by 10-months while maladaptive ER stress response was seen at 15- and 20-months of age along with impaired UPS and autophagy, and perturbations in neuronal growth factors. All these disturbances intensify with age to further exaggerate cell death mechanisms. There was a shrinkage of the cell size with aging and Congo-red staining revealed β-amyloid accumulation in higher ages. Together these results suggest that progressive accumulation of AGEs with aging in the brain may lead to neuronal damage by affecting ER homeostasis, UPS, autophagic flux, and neuronal growth factors.

Design of SnO2:Ni,Ir Nanoparticulate Photoelectrodes for Efficient Photoelectrochemical Water Splitting.

Currently, hydrogen generation via photocatalytic water splitting using semiconductors is regarded as a simple environmental solution to energy challenges. This paper discusses the effects of the doping of noble metals, Ir (3.0 at.%) and Ni (1.5–4.5 at.%), on the structure, morphology, optical properties, and photoelectrochemical performance of sol-gel-produced SnO2 thin films. The incorporation of Ir and Ni influences the position of the peaks and the lattice characteristics of the tetragonal polycrystalline SnO2 films. The films have a homogeneous, compact, and crack-free nanoparticulate morphology. As the doping level is increased, the grain size shrinks, and the films have a high proclivity for forming Sn–OH bonds. The optical bandgap of the un-doped film is 3.5 eV, which fluctuates depending on the doping elements and their ratios to 2.7 eV for the 3.0% Ni-doped SnO2:Ir Photoelectrochemical (PEC) electrode. This electrode produces the highest photocurrent density (Jph = 46.38 mA/cm2) and PEC hydrogen production rate (52.22 mmol h−1cm−2 at −1V), with an Incident-Photon-to-Current Efficiency (IPCE% )of 17.43% at 307 nm. The applied bias photon-to-current efficiency (ABPE) of this electrode is 1.038% at −0.839 V, with an offset of 0.391% at 0 V and 307 nm. These are the highest reported values for SnO2-based PEC catalysts. The electrolyte type influences the Jph values of photoelectrodes in the order Jph(HCl) > Jph(NaOH) > Jph(Na2SO4). After 12 runs of reusability at −1 V, the optimized photoelectrode shows high stability and retains about 94.95% of its initial PEC performance, with a corrosion rate of 5.46 nm/year. This research provides a novel doping technique for the development of a highly active SnO2-based photoelectrocatalyst for solar light-driven hydrogen fuel generation.

A case of successful conversion surgery for locally advanced pancreatic cancer with synchronous triple cancer of the lung and esophagus: a case report

BackgroundThe number of reports of multiple primary cancer (MPC) is increasing because of the advancement in diagnostic imaging technology. However, the treatment strategy for MPCs involving pancreatic cancer is controversial because of the extremely poor prognosis. We herein report a patient with synchronous triple cancer involving the pancreas, esophagus, and lung who underwent conversion surgery after intensive chemotherapy for unresectable locally advanced pancreatic cancer.Case presentationA 59-year-old man was admitted to our hospital with epigastric pain, anorexia, and weight loss. Computed tomography and upper gastrointestinal endoscopy revealed that the patient had synchronous triple cancer of the pancreas, esophagus, and lung. While the esophageal and lung cancer were relatively non-progressive, the pancreatic tail cancer had invaded the aorta, celiac axis, and left kidney, and the patient was diagnosed with unresectable locally advanced disease. Because the described lesion could have been the prognostic determinant for this patient, we initiated intensive chemotherapy (gemcitabine plus nab-paclitaxel) for pancreatic cancer. After six courses of chemotherapy, the tumor size shrank remarkably and no invasion to the aorta or celiac axis was observed. No significant changes were observed in the esophageal and lung cancers; endoscopic submucosal dissection could be still a curative treatment for the esophageal cancer. Therefore, we performed curative resection for pancreatic cancer (distal pancreatomy, splenectomy, and left nephrectomy; ypT3N0cM0, ypStage IIA, UICC 8th). Pathologically, complete resection was achieved. The patient then underwent endoscopic submucosal dissection for early esophageal cancer (pT1a[M]-LPM) and video-assisted thoracoscopic right upper lobectomy in combination with right lower partial resection for early lung cancer (pT2aN0M0, pStage IB, UICC 8th). Eight months after pancreatic cancer surgery, the patient is alive and has no sign of recurrence; as a result of the successful treatment, the patient has a good quality of life.ConclusionsTreatment of MPC is challenging, especially for cases with unresectable tumors. Although synchronous triple cancer can involve unresectable pancreatic cancer, radical resection may be possible after careful assessment of the appropriate treatment strategy and downstaging of unresectable tumors.

Nanoconfined methane density over pressure and temperature: Wettability effect

Clear knowledge about nanoconfined methane density is helpful for original gas-reserve evaluation, and production prediction in shale gas reservoirs. Although great efforts had been devoted to shedding light on this issue, the wettability effect, an impact induced by surface affinity towards methane molecules, has not received due attention. However, shale rock is composed of organic matter and inorganic matter, suggesting a wide range of surface affinity strength, as a result, figuring out the wettability effect on methane density inside nanopores is significantly necessary. In this article, the wettability effect is coupled with a previously established model for adsorption phase thickness, then the effective pore radius can be described as a function of surface contact angle, and primary pore size. After that, capturing the relative strength between fluid-fluid interaction and fluid-surface interaction, a robust model manifesting the shift of methane critical properties, as well as surface contact angle, is developed. Subsequently, a modified PR-EOS is utilized to calculate methane density, incorporating effective pore size and nanoconfined methane critical properties, both of which are correlated to the wettability effect. The model reliability is clarified with excellent agreements against methane density in bulk condition, and a total of 46 nanoconfined densities collected from previous contributions. Results show that (a) For a specified wettability effect, the shrinkage of pore size plays a detrimental role for the enhancement of methane density, its magnitude can reach 20%; (b) Weak surface affinity contributes to the increasing methane density, while the impact will be greatly mitigated in large pores; (c) Methane density in cylindrical nanopores is less than that in slit nanopores, stemming from the strong surface-fluid interactions in nanoscale cylindrical geometry. The article provides a practical yet reliable approach to evaluate nanoconfined methane density, expecting to enrich development theory for shale gas reservoirs.

Microenvironment-activatable cascaded responsive carbonized polymer dots as a theranostic platform for precise rapamycin delivery to potentiate the synergy of chemotherapy and γδ T cells-mediated immunotherapy against tumor

The combination of chemotherapy and immunotherapy (also known as chemo/immunotherapy) promoted by nanomedicine has the potential to enhance the therapeutic effect in more patient populations. However, it is still affected by the inactivation of immune cells induced by traditional chemotherapy, which greatly impairs the synergistic effect of chemotherapy/immunotherapy substantially. Moreover, once tumor cells lose their MHC expression, the current popular CD8+ T cell-based immunotherapy may fail consequently. Herein, rapamycin, as mTOR signaling inhibitor associated with serious side effect once systemically administered, was incorporated into shell-core theranostic nanoplatform to augment synergy of chemotherapy and γδ T cell-mediated MHC-unrestricted immunotherapy against tumor without toxicity on γδ T cells. This nano-platform assembled from a cleavable shell and a carbonized polymer dot core can achieve accurate delivery of rapamycin with traceable imaging and cascade response. Such cascaded responsiveness has endowed it with improved blood compatibility, effective tumor accumulation, microenvironment-selective endocytosis, and hierarchical drug release facilitated by microenvironment-triggered programmable properties (size shrinkage, charge conversion and degradability) transition responding to blood-tissue-cells multi-level biological barriers. In vitro and in vivo experiments have shown that the nanoplatform not only promotes tumor chemotherapy by down-regulating mTOR signals, but also enhances γδ T cell-mediated immunotherapy by promoting the NKG2D pathway in a microenvironment-selective manner. In addition, the TCR-δ knockout mouse model was used to verify the synergy of chemical/immunotherapy promoted by the nanoplatform. In addition to multifunctional integrated therapeutic and diagnostic strategies, we also provide a paradigm to enhance the synergistic effect of chemotherapy/immunotherapy, and broaden the horizons of immunotherapy through γδ T cell-mediated replacement therapy assisted by nano-drugs.

Effectiveness of Vacuum-assisted Closure (VAC) Therapy for Open Musculoskeletal Injuries: A Cross-Sectional Study

Introduction: Treatment of wounds is a crucial process that requires an event of cell migration to control blood perfusion and repair in a short time period. The series of cell migration involves debris removal, infection control, reducing inflammation, formation of granulation tissue. Aim: To examine the effectiveness of vacuum-assisted closure therapy for open musculoskeletal injuries. Methodology: All the patients underwent the standard radiological assessment. We performed a routine hematological investigation. We gently placed the open-pore foam (35 PPI density and 33 mm thick) dressing into the cavity of the wound. We used 400–600 microns size polyurethane open-pore foam because these foams are effective at transmitting mechanical forces across the wound also assist wound healing by applying pressure on the entire wound. The drape was used to seal the wound site. Study design: A cross-sectional study. Place and Duration: This study was conducted at Muhammad Medical College and Hospital Mirpurkhas, PHQ Hospital Gilgit, Fauji Foundation Hospital, Rawalpindi Pakistan from June 2020 to June 2021. Results: For this study, we recruited 30 patients with a mean age of 39 ± 18 years. All the selected patients had acute trauma. We observed 13.33% cases with decreased wound size greater than 25mm over 8 days however no significant difference was found between 0 to 8 days. The overall mean difference of wound size was reported as 13.24 8.48 with a significant p-value of 0.0001 which depicts a significant shrink in wound size over time. Regarding bacterial growth, we observed that at day 0 all patients reported bacterial growth which reduces to 40% cases at day 8. Conclusion: Outcomes of our study revealed that vacuum-assisted closure therapy is an effective method for managing open musculoskeletal injuries. Sub atmospheric pressure reduces blood perfusion, increases the formation of granulation tissue, and also minimizes tissue bacterial growth.

Atomic-scale manufacture of metre-sized two-dimensional single crystals by interfacial modulation

With the shrinkage of the chip feature size, the short-channel effect becomes more and more predominate. The development of new quantum materials for high-performance devices has become imperative for the current technological development. Two-dimensional (2D) materials, due to their excellent physical and chemical properties, are thought to be the promising candidate of quantum materials for achieving the high-end electronic and optoelectronic devices. Like the development of silicon-based chips, the wafer-scale device applications of 2D materials must be based on the fabrication of high-quality, large-size 2D single crystals. However, the existing manufacturing techniques of the well-studied bulk single crystals cannot be fully applied to the fabrication of 2D single crystals due to the interfacial characteristics of 2D materials. So far, single crystals of metre-sized graphene, decimetre-sized hBN and wafer-sized TMDCs have been successfully prepared by chemical vapor deposition, but the sizes of other 2D single crystals are still very limited and not in the same league as conventional semiconductor materials. Therefore, it is urgent to develop an effective preparation strategy for the manufacture of various 2D single crystals. In this review, we mainly overview the fabrication techniques for the meter-scale growth of 2D single crystals, and propose three key modulation aspects in the atomic-scale manufacture, i.e. the growth modulation of 2D single nucleus, the preparation of single-crystal substrates, and the alignment control of 2D single-crystal domains, in order to provide a universal method of fabricating the large-size 2D single crystals. Finally, the prospect of chip devices based on these high-quality large-size novel 2D single crystals is discussed, thereby paving the way for the future industrial applications of electronics and optoelectronics.

Effects of Wheel Rotation on Long-Period Wake Dynamics of the DrivAer Fastback Model

Lattice Boltzmann method (LBM) simulations were performed to capture the long-period dynamics within the wake of a realistic DrivAer fastback model with stationary and rotating wheels. The simulations showed that the wake developed as a low-pressure torus regardless of whether the wheels were rotating. This torus shrank in size on the base in the case of rotating wheels, leading to a reduction in the low-pressure footprint on the base, and consequently a 7% decrease in the total vehicle drag in comparison to the stationary wheels case. Furthermore, the lateral vortex shedding experienced a long-period switching associated with the bi-stability in both the stationary and rotating wheels cases. This bi-stability contributed to low-frequency side force oscillations (<1 Hz) in alignment with the peak motion-sickness-inducing frequency (0.2 Hz).

Inferior vena cava thrombus shrinkage in patient with adult Wilms' tumor: A Case report.

Introduction and importanceAdult Wilms' tumor is infrequent in adults and usually has poor prognosis. We report a case of inferior vena cava thrombus shrinkage in patient with adult Wilms' tumor.Case presentationA 27-year-old male came to hospital due to pain in his left flank and repeated hematuria since one year ago. An inhomogeneous mass and thrombus in IVC and abdominal aorta near renal artery were found from his abdominal CT scan with contrast, so cytoreductive nephrectomy was performed. However, the patient was unstable during operation so the thrombus couldn't be operated. Post-op immuno-histo-chemistry evaluation conethicfirmed the diagnosis of adult Wilms Tumor. A follow-up CT scan with contrast showed shrinkage of thrombus size with no sign of peripheral congestion. This phenomenon was rare in adult Wilms tumors, especially when the patient didn't undergo thrombus removal or adjuvant chemotherapy.Clinical discussionAdult Wilms' tumor tends to invade blood vessels in the form of thrombus, as shown in this case. Up to 4% of patients with thrombus had it around vena cava [3,4]. The recommended treatment is open surgery. Patients with chronic thrombus obstruction might have several venous collateral pathways to maintain blood flow to the right atrium. Generally, there are three major alternative pathways found in such complications.ConclusionThis study presented a patient with adult Wilms' tumor that experienced post-operative thrombus shrinkage without doing adjuvant chemotherapy or thrombus removal during surgery.

Implementation of Nanoscale Secondary‐Ion Mass Spectrometry Analyses: Application to Ni‐Based Superalloys

Secondary‐ion mass spectrometry (SIMS) is probably the most widely used chemical analysis technique in semiconductor science and in metallurgy because of its ultimate sensitivity to all elements and in particular to light elements providing semiquantitative information on the depth distribution of elements, for instance, doping elements (i.e., B, H), contaminants (i.e., C and O), chemical gradients, and segregation in thin films and at interfaces, etc. With the size shrinking of systems, high‐resolution 3D chemical imaging is becoming a prerequisite for the development of new materials at the nanoscale and for the deep understanding of the correlation between their properties and functionalities. Herein, the development of an innovative analytical SIMS implemented in a focused ion beam (FIB) (using Ga source)/scanning electron microscope (SEM) is reported. The equipment enables to give elemental chemical mapping at very high resolution (<30 nm) by precise optimization of the secondary‐ion optics and detection, while preserving excellent sensitivity, thanks to the integration of a gas injection system (GIS), which improves a positive (negative) ionization rate with oxygen (cesium) injection. The capability of the technique is demonstrated with nanoscale characterization of Ni‐based superalloys with broad applications in the manufacturing of engine parts and accessories for aircraft and aerospace equipment.

Assembly Transformation Jointly Driven by the LAP Enzyme and GSH Boosting Theranostic Capability for Effective Tumor Therapy

Developing intelligent and morphology-transformable nanomaterials that can spatiotemporally undergo stimulus-responsive size transformation holds great promise for improving the tumor delivery efficiency of drugs in vivo. Here, we report a smart size-transformable theranostic probe Ce6-Leu consisting of a leucine amino peptidase (LAP) and glutathione (GSH) dual-responsive moiety, an 1,2-aminothiol group, and a clinically used photosensitizer Ce6. This probe tends to self-assemble into uniform nanoparticles with an initial size of ∼80 nm in aqueous solution owing to the amphiphilic feature. Surprisingly, taking advantage of the biocompatible CBT-Cys condensation reaction, the large nanoprobes can be transformed into tiny nanoparticles (∼23 nm) under the joint action of LAP and GSH in a tumor microenvironment, endowing them with great tumor accumulation and deep tissue penetration. Concomitantly, this LAP/GSH-driven disassembly and size shrinkage of Ce6-Leu can also activate the fluorescence/magnetic resonance signals and the photodynamic effect for enhanced multimodal imaging-guided photodynamic therapy of human liver HepG2 tumors in vivo. More excitingly, the Mn2+-chelating probe (Ce6-Leu@Mn2+) was demonstrated to have the capability to catalyze endogenous H2O2 to persistently release O2 at the hypoxic tumor site, as a consequence improving the oxygen supply to boost the radiotherapy effect. We thus believe that this LAP/GSH-driven size-transformable nanosystem would offer a novel advanced technology to improve the drug delivery efficiency for achieving precise tumor diagnosis and treatment.

Characterization of externally solidified crystals in a high-pressure die-cast AlSi10MnMg alloy and their effect on porosities and mechanical properties

The characterization of externally solidified crystals (ESCs) and porosities in a high-pressure die-cast AlSi10MnMg alloy was investigated using optical microscope (OM) and computed tomography (CT) with particular attention on the effect of shot speeds on the ESCs and fracture behavior. Results showed that ESCs tended to agglomerate at the center region and changed from fine globular grains into large size dendrites from surface to center. The formation of the ESCs is found to be coarser as the "slow shot speed" in the first stage of high-pressure die casting (HPDC) or the "fast shot speed" in the second stage of HPDC is reduced, consequently, the corresponding ESC area fraction increased. From the fractured morphology, the plate specimen with a higher ESC content exhibited a rough fracture and a large volume fraction of shrinkage porosities was discovered beneath the fracture surface especially when a lower fast shot speed was applied. In in-situ tensile test, the large size shrinkage porosity served as a crack source and it further expanded in an inter-granular mode along ESC boundaries/other porosities (which caused a tortuous crack route) or in a trans-granular mode across the ESC grains/fine (α-Al) II grains (which caused a flat crack route). In addition, the gas porosities in the specimen promoted the crack propagation as a crack concentration area and experienced almost no deformation during the tensile process.

Predicting Pathological Complete Response After Neoadjuvant Chemotherapy in Advanced Breast Cancer by Ultrasound and Clinicopathological Features Using a Nomogram.

Background and AimsPrediction of pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) for breast cancer is critical for surgical planning and evaluation of NAC efficacy. The purpose of this project was to assess the efficiency of a novel nomogram based on ultrasound and clinicopathological features for predicting pCR after NAC.MethodsThis retrospective study included 282 patients with advanced breast cancer treated with NAC from two centers. Patients received breast ultrasound before NAC and after two cycles of NAC; and the ultrasound, clinicopathological features and feature changes after two cycles of NAC were recorded. A multivariate logistic regression model was combined with bootstrapping screened for informative features associated with pCR. Then, we constructed two nomograms: an initial-baseline nomogram and a two-cycle response nomogram. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were analyzed. The C-index was used to evaluate predictive accuracy.ResultsSixty (60/282, 21.28%) patients achieved pCR. Triple-negative breast cancer (TNBC) and HER2-amplified types were more likely to obtain pCR. Size shrinkage, posterior acoustic pattern, and elasticity score were identified as independent factors by multivariate logistic regression. In the validation cohort, the two-cycle response nomogram showed better discrimination than the initial-baseline nomogram, with the C-index reaching 0.79. The sensitivity, specificity, and NPV of the two-cycle response nomogram were 0.77, 0.77, and 0.92, respectively.ConclusionThe two-cycle response nomogram exhibited satisfactory efficiency, which means that the nomogram was a reliable method to predict pCR after NAC. Size shrinkage after two cycles of NAC was an important in dependent factor in predicting pCR.

Spatio-Temporal Characteristics of Dry-Wet Conditions and Boundaries in Five Provinces of Northwest China from 1960 to 2020

The study of dry-wet climate boundaries in the context of climate warming is of great practical significance for improving the environment of ecologically fragile zones and promoting economic and natural sustainable development. In this study, based on the daily meteorological data of 110 stations, using the wetness index, empirical orthogonal function decomposition, regime shift detection test, Fourier power spectrum, and Kriging interpolation, the researchers analyzed the spatiotemporal characteristics of dry-wet conditions and boundaries in five provinces of Northwest China from 1960 to 2020. The results showed that the overall wetness index increased in the past 61 years, but with significant internal differences, among which the western and central climate tended to be warm and wet, and the eastern tended to be warm and dry. The annual wetness index changed abruptly in 1986 with cycles of 3.61 a, 7.11 a and 8.83 a. The mutations occurred correspondingly in spring, summer, autumn, and winter in 1972, 1976, 1983, and 1988, with periods of 3.88 a and 4.92 a, 2.18 a and 2.81 a, 2.15 a, and 2.10 a, respectively. The dry-wet climate boundary has fluctuated markedly since 1960. The extreme arid and arid regions boundary shifted southward and shrank in size until the extreme arid region disappeared in the 2010s. The arid along with semi-arid regions and semi-arid in addition to semi-humid regions boundaries both have two boundary lines, and show the shift of the northwestern boundary to the southeast and the southeastern boundary to the northwest, with the area of the arid together with semi-arid regions shrinking significantly by 5.64%, simultaneously, the area of the semi-humid region area expanding significantly by 84.11%. The boundary of semi-humid and relatively humid regions, and the boundary of relatively humid and humid regions all shifted to the southeast, moreover, the area of the relatively humid region and humid region shrank significantly by 12.08%. The expansion of semi-humid region and the contraction of other climate regions are characteristics of the dry-wet climate variability in five provinces of Northwest China. The area of the three arid climate zones dwindled by 9.61%, and the area of the three humid zones extended by 39.01%. Obviously, the climate inclined to be warm and humid in general.

Programming-level and redundancy-free method for enhancing software reliability against transient errors in hardware

Software play remarkable roles in different critical applications. On the other hand, due to the shrinking of transistor size and reduction in supply voltage, radiation-induced transient errors (soft errors) have become an important source of computer systems failure. As the rate of transient hardware faults increases, researchers have investigated software techniques to control these faults. Performance overhead is the main drawback of software-implemented methods like recovery blocks that use technical redundancy. Enhancing the software reliability against soft errors by utilizing inherently error masking (invulnerable) programming structures is the main goal of this study. During the programming phase and at the source code level, programmers can select different storage classes such as automatic, global, static and register for the data into their program without paying attention to their inherent reliability. In this study, the inherent effects of these storage classes on the program reliability are investigated. Extensive series of profiling and fault-injection experiments were performed on the set of benchmark programs implemented with different storage classes. Regarding the results of experiments, we find that the programs implemented with automatic storage classes have inherently higher reliability than the programs with static and register storage classes without performance overhead. This finding enables the programmers to develop highly reliable programs without technical redundancy and performance overhead.

Frequent ploidy changes in Salicaceae indicates widespread sharing of the salicoid whole genome duplication by the relatives of Populus L. and Salix L.

BackgroundsPopulus and Salix belong to Salicaceae and are used as models to investigate woody plant physiology. The variation of karyotype and nuclear DNA content can partly reflect the evolutionary history of the whole genome, and can provide critical information for understanding, predicting, and potentially ameliorating the woody plant traits. Therefore, it is essential to study the chromosome number (CN) and genome size in detail to provide information for revealing the evolutionary process of Salicaceae.ResultsIn this study, we report the somatic CNs of seventeen species from eight genera in Salicaceae. Of these, CNs for twelve species and for five genera are reported for the first time. Among the three subfamilies of Salicaceae, the available data indicate CN in Samydoideae is n = 21, 22, 42. The only two genera, Dianyuea and Scyphostegia, in Scyphostegioideae respectively have n = 9 and 18. In Salicoideae, Populus, Salix and five genera closely related to them (Bennettiodendron, Idesia, Carrierea, Poliothyrsis, Itoa) are based on relatively high CNs from n = 19, 20, 21, 22 to n = 95 in Salix. However, the other genera of Salicoideae are mainly based on relatively low CNs of n = 9, 10, 11. The genome sizes of 35 taxa belonging to 14 genera of Salicaceae were estimated. Of these, the genome sizes of 12 genera and all taxa except Populus euphratica are first reported. Except for Dianyuea, Idesia and Bennettiodendron, all examined species have relatively small genome sizes of less than 1 pg, although polyploidization exists.ConclusionsThe variation of CN and genome size across Salicaceae indicates frequent ploidy changes and a widespread sharing of the salicoid whole genome duplication (WGD) by the relatives of Populus and Salix. The shrinkage of genome size after WGD indicates massive loss of genomic components. The phylogenetic asymmetry in clade of Populus, Salix, and their close relatives suggests that there is a lag-time for the subsequent radiations after the salicoid WGD event. Our results provide useful data for studying the evolutionary events of Salicaceae.

Employing Genome-Wide SNP Discovery to Characterize the Genetic Diversity in Cinnamomum camphora Using Genotyping by Sequencing

Cinnamomum camphora (L.) J.Presl is a representative tree species of evergreen broad-leafed forests in East Asia and has exceptionally high economic, ornamental, and ecological value. However, the excessive exploitation and utilization of C. camphora trees have resulted in the shrinking of wild population sizes and rare germplasm resources. In this study, we characterized 171 C. camphora trees from 39 natural populations distributed throughout the whole of China and one Japanese population. We investigated genetic diversity and population structure using genome-wide single-nucleotide polymorphism (SNP) identified by genotyping by sequencing (GBS) technology. The results showed the genetic diversity of the C. camphora populations from western China > central China > eastern China. Moreover, the Japanese population showed the highest diversity among all populations. The molecular variance analysis showed 92.03% of the genetic variation within populations. The average pairwise FST was 0.099, and gene flow Nm was 2.718, suggesting a low genetic differentiation among populations. Based on the genetic clustering analysis, the 40 C. camphora populations clustered into three major groups: Western China, Central China, and Eastern China + Japan. Eastern China’s population had the closest genetic relationship with the Japanese population, suggesting possible gene exchange between the two adjacent areas. This study furthers our understanding of the genetic diversity and genetic structure of C. camphora in East Asia and provides genetic tools for developing strategies of C. camphora germplasm utilization.