[The role of cell division cycle 42 in root development of tooth and the involved mechanisms]

Objective: To explore the effect of cell division cycle 42 (CDC42) on root development and its regulation on cell proliferation and migration in Hertwig's epithelial root sheath (HERS). Methods: Trace the spatiotemporal expression of CDC42 in root development process [postnatal day 5 (P5), P7, P14] through immunofluorescence staining. Nine eight-week-old C57BL/6J male mice were randomly divided into 3 groups using a simple random sample method (n=3 in each group). P3 tooth germ was cultured in air-liquid system for 1 day and then transplanted to renal capsule each to observe tooth root development. The control group implanted tooth germ only. The phosphate buffered saline (PBS) group implanted tooth germ and gel beads soaked with PBS, while the ML141 group implanted tooth germ and gel beads soaked with CDC42 inhibitor (ML141). Cdc42 in HERS cells was inhibited via lentivirus transfection. Cell counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay and scratch assay were performed. The distribution of Golgi apparatus (GM130) and cytoskeleton (F-actin) in migrated cells were mapped via immunofluorescence staining. Results: CDC42 was expressed in epithelial cells of HERS, polarized ameloblasts and odontoblasts, as well as adjacent dental papilla and dental follicle cells during tooth root development. The root length of the ML141 group [(0.61±0.09) mm] was substantially shorter than that of control group [(1.03±0.19) mm, P=0.007] and PBS group [(0.98±0.10) mm, P=0.021] according to the data of renal capsule transplantation. After lentiviral transfection, the relative expression of Cdc42 in knockdown group (0.31±0.33) was significantly lower than that in control group (1.05±0.08) (t=15.38, P<0.001), demonstrating the knockdown efficiency closed to 70%. Cell viabilities were significantly inhibited in knockdown group (0.87±0.04, 0.96±0.10, 0.59±0.06, respectively) compared with those in control group (1.09±0.13, 1.55±0.32, 1.10±0.09, respectively) after 3, 4 and 5 days (t=3.16, P=0.016; t=4.23, P=0.002; t=5.08, P<0.01), and the cell proliferation ability in knockdown group [(1.65±0.64)%] also decreased than that in the control group [(4.02±1.12)%](t=5.21, P<0.001). In addition, the cell migration rates after 24 and 48 h [(45.1±4.2)%, (56.4±8.3)%] in knockdown group were obviously lower than those in the control group [(63.8±7.4)%, (80.2±7.8)%] (t=3.78, P=0.019; t=3.62, P=0.023). After Cdc42 was knocked down, Golgi apparatus distributed along the nucleus while behaved oriented in the control group. Conclusions: CDC42 plays an important role in the regulation of root length during root development, which may mediate root elongation by affecting the migration and proliferation of HERS cells.

Symptom burden, psychological distress, and symptom management status in hospitalized patients with advanced cancer: a multicenter study in China

BACKGROUND

The management of physical symptoms and psychological distress of cancer patients is an important component of cancer care. The purpose of this study was to evaluate the symptom burden, psychological distress, and management status of hospitalized patients with advanced cancer in China and explore the potential influencing factors of undertreatment and non-treatment of symptoms.

PATIENTS AND METHODS

A total of 2930 hospitalized patients with advanced cancer (top six types of cancer in China) were recruited from 10 centers all over China. Patient-reported MD Anderson Symptom Inventory, Hospital Anxiety and Depression Scale (HADS), and Patient Health Questionnaire-9 (PHQ-9) scales and symptom management-related information were collected and linked with the patient's clinical data. The proportion of patients reporting moderate-to-severe (MS) symptoms and whether they were currently well managed were examined. Multivariable logistic regression models were applied to explore the factors correlated to undertreatment and non-treatment of symptoms.

RESULTS

About 27% of patients reported over three MS symptoms, 16% reported over five, and 9% reported over seven. Regarding psychological distress, the prevalence of HADS-anxiety was 29% and that of PHQ-9 depression was 11%. Sixty-one percent of patients have at least one MS symptom without any treatment. Sex [odds ratio (OR) = 2.238, 95% confidence interval (95% CI) 1.502-3.336], Eastern Cooperative Oncology Group (ECOG; OR = 0.404, 95% CI 0.241-0.676), and whether currently undergoing anticancer treatment (OR = 0.667, 95% CI 0.503-0.886) are the main factors correlated with the undertreatment of symptoms. Age (OR = 1.972, 95% CI 1.263-3.336), sex (OR = 0.626, 95% CI 0.414-0.948), ECOG (OR = 0.266, 95% CI 0.175-0.403), whether currently undergoing anticancer treatment (OR = 0.356, 95% CI 0.249-0.509), and comorbidity (OR = 0.713, 95% CI 0.526-0.966) are the main factors correlated with the non-treatment of symptoms.

CONCLUSIONS

This study shows that hospitalized patients with advanced cancer had a variety of physical and psychological symptoms but lacked adequate management and suggests that a complete symptom screening and management system is needed to deal with this complex problem.

First Measurement of the Z→μ^{+}μ^{-} Angular Coefficients in the Forward Region of pp Collisions at sqrt[s]=13 TeV

The first study of the angular distribution of μ^{+}μ^{-} pairs produced in the forward rapidity region via the Drell-Yan reaction pp→γ^{*}/Z+X→ℓ^{+}ℓ^{-}+X is presented, using data collected with the LHCb detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1  fb^{-1}. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the Z-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton.

The apparent metabolisable energy requirement of Sansui ducks from hatch to 21 days of age

A dose-response experiment was conducted to estimate optimal dietary apparent metabolisable energy requirement (AME) in Sansui ducks (Sansui Sheldrake duck) from hatch to 21 days of age. Three hundred thirty-six one-day-old male Sansui ducks were randomly assigned to six experimental treatments, each consisting of seven replicate pens with eight birds per pen. Birds were fed diets containing either 10.92, 11.38, 11.8, 12.26, 12.68 and 13.14 MJ AME/kg, respectively. At 21 d of age, the body weight, weight gain, feed intake, protein intake, energy intake and feed conversion ratio of ducklings from each pen were measured. Increasing AME content from 10.92 MJ/kg to 13.14 MJ/kg significantly improved body weight, weight gain, feed intake, feed conversion ratio and crude protein intake (P<0.05). No significant changes in energy intake were found among treatments (P>0.05). Based on broken-line regression analysis, the AME requirement of male Sansui ducks from hatch to 21 d of age was 11.49 and 11.59 MJ/kg for maximum body weight and best feed conversion ratio, respectively.

[Development of a nomogram for predicting the risk of colorectal advanced adenomas]

Objective: To explore the risk factors of colorectal advanced adenomas (AA) and construct a nomogram to predict the risk of colorectal AAs. Methods: Clinical data of patients were retrospectively collected who underwent their first colonoscopy from January 2017 to December 2020 in the First Affiliated Hospital of Nanjing Medical University and were pathologically confirmed harboring colorectal polyps. A credible random split-sample method was used to divide data into training and validation cohorts (split ratio=7∶3). Univariate and multivariate logistic regression analysis were used to identify the predictors of colorectal advanced adenomas, and a nomogram was developed based on the above results. The validation cohort was used for internal validation of the nomogram. The discriminatory value of the nomogram was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC). The consistency between actual outcomes and predicted probabilities was evaluated by the calibration curve. The clinical validity of the model was evaluated by the decision analysis curve (DCA). Results: A total of 1 936 patients with colorectal polyps were eligible. Including 1 356 patients in the training cohort (840 males and 516 females), and 580 patients in the validation cohort (379 males and 201 females), with the mean ages of (57.4±9.8) and (57.6±9.7) years, respectively. There were 1 502 (77.6%) patients without AAs and 434 [22.4%,1-9 mm 73(16.8%) cases、>9-<20 mm 271(62.5%) cases、≥20 mm 90(20.7%) cases] patients with AAs. The regression analysis found that age (OR=1.018, 95%CI:1.003-1.033), fatty liver (OR=1.870, 95%CI:1.274-2.744), low-density lipoprotein (LDL) (OR=1.378, 95%CI:1.159-1.637), fecal occult blood test (FOBT) (OR=2.597, 95%CI:1.857-3.631), and location of adenomas [proximal (OR=2.869, 95%CI:1.727-4.764), distal (OR=2.791, 95%CI:1.721-4.527)] were identified as predictors of colorectal AAs. The AUC of the nomogram was 0.664 (95%CI:0.630-0.698) in the training cohort and 0.640 (95%CI:0.587-0.693) in the validation cohort. The calibration curve showed good consistency between the predicted and actual risk, and the Hosmer-Lemeshow (H-L) test P value was 0.830 and 0.150 in the training cohort and the validation cohort. DCA demonstrated that the nomogram had a better clinical application value. Conclusions: A nomogram with five predictors, including age, fatty liver, LDL, FOBT, and location of adenomas, helped predict the risk of colorectal AAs in patients with polyps and implemented colorectcal cancer stratified screening strategy for colonoscopy in the high-risk population.

Conceptual design and performance predictions for 2D beam emission spectroscopy turbulence measurements at Wendelstein 7-X

A conceptual design for a 2D beam emission spectroscopy diagnostic system to measure ion gyro-scale plasma turbulence at Wendeslstein 7-X is described. The conceptual design identifies field-aligned viewing geometries and ports for cross-field turbulence measurements in the neutral beam volume. A 2D sightline grid covers the outer plasma region, and the grid configuration provides sufficient k-space coverage in radial and poloidal directions for ion temperature gradient and trapped-electron mode turbulence measurements. Emission intensity estimates, optical transmission losses, and detector noise levels indicate that the measurements will be sensitive to plasma density fluctuations as small as δn/n ≈ 0.5% with a bandwidth of 1 MHz. Implementation challenges include a small beam emission Doppler shift due to nearly radial heating beams and reduced optical throughput due to collection aperture limitations.

Ultrafast soliton delivered by miniaturized mode-locker with MoTe2 and core-expanded fiber

Thermally expanded core (TEC) technology is an effective method of high-power fiber lasers. Miniaturization is also a major challenge for high-power lasers. We have proposed a miniaturized mode-locker based on TEC fiber and MoTe₂-polyvinyl alcohol (PVA) film. The proposed mode-locker is consisting of two TEC ferrules, a piece of MoTe₂-PVA film and a ceramic sleeve. The length of the proposed device is about 20 mm, and its outer diameter is about 2 mm. The relations between heating time, heating temperature, and mode field diameter (MFD) have been numerically simulated. The bending loss with respect to MFD has also been analyzed. The simulation results have revealed the trade-off relation between maximal tolerable intensity and low cavity loss, which means that there is an optimal MFD corresponding to optimal heating time and heating temperature. The proposed mode-locker has been applied in an integrated fiber laser, which has emitted ultrafast soliton with 3 times intensity larger than that of conventional sandwiched-type saturable absorber. The proposed mode-locker and fiber laser will find important applications in laser processing, laser ranging, and optical communication.

Study of the doubly charmed tetraquark [Formula: see text]

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar [Formula: see text] tetraquark with a quark content of [Formula: see text] and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector [Formula: see text] state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the [Formula: see text] state. In addition, an unexpected dependence of the production rate on track multiplicity is observed.

Angular Analysis of D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} Decays and Search for CP Violation

The first full angular analysis and an updated measurement of the decay-rate CP asymmetry of the D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays are reported. The analysis uses proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. The dataset corresponds to an integrated luminosity of 9  fb^{-1}. The full set of CP -averaged angular observables and their CP asymmetries are measured as a function of the dimuon invariant mass. The results are consistent with expectations from the standard model and with CP symmetry.

Safety, pharmacokinetics, and efficacy of BPI-15086 in patients with EGFR T790M-mutated advanced non-small-cell lung cancer: results from a phase I, single-arm, multicenter study

Background

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) resistance frequently occurs in patients with non-small-cell lung cancer (NSCLC). EGFR Thr790Met mutation (T790M+) is seen in ∼50% of patients. We assessed the safety, tolerability, and pharmacokinetics (PK) of BPI-15086, a novel, ATP-competitive, irreversible, third-generation, mutation-selective EGFR-TKI in patients with EGFR T790M-mutated NSCLC.

Patients and methods

This two-center, phase I, dose-escalation study included patients who were 18-65 years old, with an Eastern Cooperative Oncology Group performance status of 0-2, with histologically or cytologically confirmed locally advanced or metastatic T790M+ NSCLC who were not surgical or radiotherapy candidates, and had imaging-identified disease progression after prior EGFR-TKIs. This dose-escalation study enrolled patients using a 3 + 3 study design. Patients received 25, 50, 100, 200, and 300 mg/day orally in 21-day cycles. The primary endpoints were safety, tolerability, and PK. Secondary endpoints were objective response rate (ORR) and disease control rate (DCR). The dose-expansion study was not conducted.

Results

We enrolled 17 patients from 29 December 2016 to 16 May 2018, in the safety and full analysis sets. All patients completed a single dosing trial, and no adverse events (AEs) causing drug discontinuation were seen. Grade 1-2 nausea, hypoalbuminemia, and decreased appetite were the most common treatment-related AEs. Grade 3 hyperglycemia was seen in one patient dosed at 300 mg/day. The ORR and DCR were 17.7% [95% confidence interval (CI) 3.8% to 43.4%] and 47.1% (95% CI 23.0% to 72.2%), respectively.

Conclusion

BPI-15086 is a safe and tolerable third-generation EGFR-TKI with a rationale for further clinical studies.

•

BPI-15086 is safe and has partial effectiveness in patients with advanced T790M+ NSCLC after previous EGFR-TKI therapy.

•

A different safety profile for BPI-15086 compared with other third-generation EGFR-TKIs.

•

The modest efficacy in this study is still deemed important and should be added to the literature of third-generation TKIs.

POS0413 IGURATIMOD AMELIORATES BLEOMYCIN-INDUCED PULMONARY FIBROSIS VIA INHIBITINGEMT PROCESS AND NLRP3 INFLAMMASOME ACTIVATION

Background

Interstitial pulmonary fibrosis is the deadliest manifestation of rheumatoid arthritis (RA), and its pathogenesis is complicated. As a new drug for controlling RA, clinical studies have found that iguratimod (IGU) has certain advantages in improving lung function and shows great potential for pulmonary fibrosis therapy[1]. However, the specific mechanism of IGU in treating pulmonary fibrosis is not clear.

Objectives

This study was designed to observe and investigate the therapeutic effects of IGU on bleomycin-induced pulmonary fibrosis in mice and further investigate its underlying mechanism, aiming to provide a further theoretical basis for clinical rational drug use.

Methods

A mouse model of pulmonary fibrosis was induced by intratracheal injection of bleomycin (BLM)[2]. Model mice were randomly assigned to receive Sodium carboxymethyl cellulose (CMC) or different concentrations of IGU. HE staining and immunohistochemical staining were performed to observe the therapeutic effects of IGU on mouse fibrosis. TGF-β induced A549 EMT cell model was utilized to investigate the effects of IGU on EMT in vitro[3]. NLRP3 inflammasome was activated by the co-stimulation of TGF-β+LPS+ATP (TLA) to evaluate the effects of IGU in vitro[4].

Results

We found that IGU resulted in favorable therapeutic outcomes by affecting the inflammation infiltration (Figure 1A) and collagen deposition (Figure 1B). Immunohistochemical results showed that IGU downregulated the levels of α-SM and NLRP3. Additionally, the markers of BLM-mediated EMT (Figure 1C) phenotype and NLRP3-activated (Figure 1D) phenotype in the lung were also attenuated after IGU administration. In vitro experiments, the results confirmed its anti-EMT effects of reducing the expression of interstitial proteins Vimentin and α-SMA and restoring the content of epithelial protein E-cadherin. Besides, IGU could inhibit NLRP3 activation by downregulating NLRP3 related marker proteins, reducing the secretion of IL-1β, and attenuating caspase-1 activity. We then found that IGU anti-EMT and anti-NLRP3 effect was accompanied by decreased ROS production.

Figure 1.

IGU ameliorates BLM-induced pulmonary inflammation and pulmonary fibrosis. (A) Representative lung micrographs of lung tissues stained with HE. Magnification, × 200. (B) Representative photographs of lung tissues stained with Masson’s trichrome staining. Magnification, × 200. (C) Representative results of western blot for E-cadherin, Vimentin, α-SMA expression in lung tissues. GAPDH was used as the endogenous control. (D) Representative results of western blot for NLRP3, caspase-1, cleaved-caspase-1 p20, IL-1β expression in lung tissues. GAPDH was used as the endogenous control.

Conclusion

IGU can inhibit the EMT process and NLRP3 inflammasome activation, reduce ROS production to ameliorate pulmonary fibrosis, which may provide new insights into the further application of IGU in Interstitial pulmonary fibrosis.

References

[1]Shu P, et al. Eur Rev Med Pharmacol Sci 2021, 25(4):4687 v Med

[2]Philipp K, et al. Eur Respir J 2020, 55(6):1901105.

[3]Justin C. H, et al. Matrix Biol 2018, 71-72:112-127.

[4]Anita A P, et al. Front Pharmacol 2020, 11:1201.

Disclosure of Interests

None declared.

Persistent influence of precession on northern ice sheet variability since the early Pleistocene

Prior to ~1 million years ago (Ma), variations in global ice volume were dominated by changes in obliquity; however, the role of precession remains unresolved. Using a record of North Atlantic ice rafting spanning the past 1.7 million years, we find that the onset of ice rafting within a given glacial cycle (reflecting ice sheet expansion) consistently occurred during times of decreasing obliquity whereas mass ice wasting (ablation) events were consistently tied to minima in precession. Furthermore, our results suggest that the ubiquitous association between precession-driven mass wasting events and glacial termination is a distinct feature of the mid to late Pleistocene. Before then (increasing), obliquity alone was sufficient to end a glacial cycle, before losing its dominant grip on deglaciation with the southward extension of Northern Hemisphere ice sheets since ~1 Ma.

Tests of Lepton Universality Using B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} Decays

Tests of lepton universality in B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} decays where ℓ is either an electron or a muon are presented. The differential branching fractions of B^{0}→K_{S}^{0}e^{+}e^{-} and B^{+}→K^{*+}e^{+}e^{-} decays are measured in intervals of the dilepton invariant mass squared. The measurements are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1} . The results are consistent with the standard model and previous tests of lepton universality in related decay modes. The first observation of B^{0}→K_{S}^{0}e^{+}e^{-} and B^{+}→K^{*+}e^{+}e^{-} decays is reported.

Observation of the Decay Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ}

The first observation of the semileptonic b-baryon decay Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ}, with a significance of 6.1σ, is reported using a data sample corresponding to 3  fb^{-1} of integrated luminosity, collected by the LHCb experiment at center-of-mass energies of 7 and 8 TeV at the LHC. The τ^{-} lepton is reconstructed in the hadronic decay to three charged pions. The ratio K=B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})/B(Λ_{b}^{0}→Λ_{c}^{+}π^{-}π^{+}π^{-}) is measured to be 2.46±0.27±0.40, where the first uncertainty is statistical and the second systematic. The branching fraction B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})=(1.50±0.16±0.25±0.23)% is obtained, where the third uncertainty is from the external branching fraction of the normalization channel Λ_{b}^{0}→Λ_{c}^{+}π^{-}π^{+}π^{-}. The ratio of semileptonic branching fractions R(Λ_{c}^{+})≡B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})/B(Λ_{b}^{0}→Λ_{c}^{+}μ^{-}ν[over ¯]_{μ}) is derived to be 0.242±0.026±0.040±0.059, where the external branching fraction uncertainty from the channel Λ_{b}^{0}→Λ_{c}^{+}μ^{-}ν[over ¯]_{μ} contributes to the last term. This result is in agreement with the standard model prediction.

Observation of Two New Excited Ξ_{b}^{0} States Decaying to Λ_{b}^{0}K^{-}π^{+}

Two narrow resonant states are observed in the Λ_{b}^{0}K^{-}π^{+} mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6  fb^{-1}. The minimal quark content of the Λ_{b}^{0}K^{-}π^{+} system indicates that these are excited Ξ_{b}^{0} baryons. The masses of the Ξ_{b}(6327)^{0} and Ξ_{b}(6333)^{0} states are m[Ξ_{b}(6327)^{0}]=6327.28_{-0.21}^{+0.23}±0.12±0.24 and m[Ξ_{b}(6333)^{0}]=6332.69_{-0.18}^{+0.17}±0.03±0.22  MeV, respectively, with a mass splitting of Δm=5.41_{-0.27}^{+0.26}±0.12  MeV, where the uncertainties are statistical, systematic, and due to the Λ_{b}^{0} mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of Γ[Ξ_{b}(6327)^{0}]<2.20(2.56) and Γ[Ξ_{b}(6333)^{0}]<1.60(1.92)  MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξ_{b}^{0} resonances.

Measurement of the Nuclear Modification Factor and Prompt Charged Particle Production in p-Pb and pp Collisions at sqrt[s_{NN}]=5 TeV

The production of prompt charged particles in proton-lead collisions and in proton-proton collisions at the nucleon-nucleon center-of-mass energy sqrt[s_{NN}]=5  TeV is studied at LHCb as a function of pseudorapidity (η) and transverse momentum (p_{T}) with respect to the proton beam direction. The nuclear modification factor for charged particles is determined as a function of η between -4.8<η<-2.5 (backward region) and 2.0<η<4.8 (forward region), and p_{T} between 0.2<p_{T}<8.0  GeV/c. The results show a suppression of charged particle production in proton-lead collisions relative to proton-proton collisions in the forward region and an enhancement in the backward region for p_{T} larger than 1.5  GeV/c. This measurement constrains nuclear PDFs and saturation models at previously unexplored values of the parton momentum fraction down to 10^{-6}.

Enhancing Wheat Disease Diagnosis in a Greenhouse Using Image Deep Features and Parallel Feature Fusion

Since the assessment of wheat diseases (e.g., leaf rust and tan spot) via visual observation is subjective and inefficient, this study focused on developing an automatic, objective, and efficient diagnosis approach. For each plant, color, and color-infrared (CIR) images were collected in a paired mode. An automatic approach based on the image processing technique was developed to crop the paired images to have the same region, after which a developed semiautomatic webtool was used to expedite the dataset creation. The webtool generated the dataset from either image and automatically built the corresponding dataset from the other image. Each image was manually categorized into one of the three groups: control (disease-free), disease light, and disease severity. After the image segmentation, handcrafted features (HFs) were extracted from each format of images, and disease diagnosis results demonstrated that the parallel feature fusion had higher accuracy over features from either type of image. Performance of deep features (DFs) extracted through different deep learning (DL) models (e.g., AlexNet, VGG16, ResNet101, GoogLeNet, and Xception) on wheat disease detection was compared, and those extracted by ResNet101 resulted in the highest accuracy, perhaps because deep layers extracted finer features. In addition, parallel deep feature fusion generated a higher accuracy over DFs from a single-source image. DFs outperformed HFs in wheat disease detection, and the DFs coupled with parallel feature fusion resulted in diagnosis accuracies of 75, 84, and 71% for leaf rust, tan spot, and leaf rust + tan spot, respectively. The methodology developed directly for greenhouse applications, to be used by plant pathologists, breeders, and other users, can be extended to field applications with future tests on field data and model fine-tuning.