Comprehensive performance evaluation of high embankments in heavy-haul railways using an improved extension model with attribute reduction algorithm

Effectively evaluating high-embankment deformation and stability is important for heavy-haul railway safety. An improved extension model with an attribute reduction algorithm was proposed for the comprehensive evaluation method. First, a hierarchical evaluation system for high embankments in heavy-haul railways was established using the attribute reduction algorithm, which includes the principal component analysis, maximum information coefficient, coefficient of variation, and improved Dempster-Shafer evidence theory. Furthermore, the improved extension model was used to evaluate high-embankment performance in heavy-haul railways. In this improved extension model, the combination weighting method, an asymmetric proximity function, and the maximum membership principle effectiveness verification were used. Finally, three high embankments in a Chinese heavy-haul railway were studied. The results illustrate that the main influencing factors for high-embankment performance in a heavy-haul railway are annual rainfall, annual temperature, and 21 other indicators. The performance of the three embankments is level III (ordinary), level II (fine), and level III (ordinary), respectively, indicating that these embankments have generally unfavourable performance. The three embankments’ performance matches field measurements, and the proposed method outperforms the Fuzzy-AHP method, cloud model, and gray relational analysis. This study demonstrates the feasibility of the proposed method in assessing the high-embankment performance under heavy axle loads.

Exceptional Strengthening Efficiency and Hardness of Ti/Mg-9Al-Zn-0.3Mn Matrix Composite

The involvement of magnesium matrix composite enhanced by metal particles, the development of low lattice mismatch interface, and the refining of particle size are all of great significance in improving strengthening efficiency. In this work, nano-crystalline Ti/Mg-9Al-Zn-0.3Mn composites were prepared by mechanical milling. The microstructure was characterized and the mechanical property was measured. After mechanical milling, the grain of the Mg matrix was refined to ~72 nm. Ti particles were smashed to submicron scale, and dispersed in the Mg matrix. In total, 68% of Ti particles were nano-scale and the average particle size was 133 nm. A nano-scale Mg₁₇Al₁₂ precipitate was found and the average particle size was approximately 44 nm. Meanwhile, coherent interfaces of Ti/Mg and Mg₁₇Al₁₂/Mg were observed, and it was found that the (101)Mg plane and (100)Ti plane inclined 12° and [044]Mg₁₇Al₁₂ was parallel to [010]Mg. The hardness of the milled Ti/Mg-9Al-Zn-0.3Mn composite was 1.98 GPa, 247% higher than the initial alloy. Milled Mg-9Al-Zn-0.3Mn alloy under the same preparation processing was used as a comparison, and the value of hardness was 1.53 GPa. Tiny Ti particles displayed excellent strengthening efficiency. Strengthening mechanisms of the milled Ti/Mg-9Al-Zn-0.3Mn composite were analyzed and the main strengthening mechanisms included the strengthening of grain boundary strengthening, Orowan strengthening, dislocation strengthening, solid solution strengthening and load-bearing strengthening, which accounted for 56.3%, 18.2%, 17.4%, 4.7% and 3.5%, respectively.

A Primal-Dual-Based Power Control Approach for Capacitated Edge Servers

The intensity of radio waves decays rapidly with increasing propagation distance, and an edge server's antenna needs more power to form a larger signal coverage area. Therefore, the power of the edge server should be controlled to reduce energy consumption. In addition, edge servers with capacitated resources provide services for only a limited number of users to ensure the quality of service (QoS). We set the signal transmission power for the antenna of each edge server and formed a signal disk, ensuring that all users were covered by the edge server signal and minimizing the total power of the system. This scenario is a typical geometric set covering problem, and even simple cases without capacity limits are NP-hard problems. In this paper, we propose a primal-dual-based algorithm and obtain an m-approximation result. We compare our algorithm with two other algorithms through simulation experiments. The results show that our algorithm obtains a result close to the optimal value in polynomial time.

[The urate-lowering efficacy of febuxostat and its relationship with residual renal function in peritoneal dialysis patients with hyperuricemia]

Objective: To investigate the urate-lowering efficacy of febuxostat in peritoneal dialysis (PD) patients with hyperuricemia (HUA) and its relationship with residual renal function. Methods: Patients with HUA who underwent PD in Ningbo First Hospital from January 2018 to October 2021 were enrolled and divided into experimental group and control group according to whether to use febuxostat. The clinical baseline data before treatment and clinical indicators during 1-12 months after treatment were collected in two groups, and the adverse reactions during the use of febuxostat were also recorded. The changes of serum uric acid, standard-reaching rate and residual renal function were compared between the two groups during the follow-up. Results: A total of 105 patients were included in the study. There were 55 patients in the experimental group [27 males and 28 females, with a mean age of (54.5±14.8) years] and 50 patients in the control group [32 males and 18 females, with a mean age of (53.8±15.2) years]. No statistically significant difference was detected in clinical baseline data between the two groups (all P>0.05). The serum uric acid of the experimental group [(479±77), (311±69), (286±61), (307±65), (312±57) μmol/L] and control group [(486±59), (454±71), (453±76), (463±70), (459±76) μmol/L] were lower than baseline values at 1, 3, 6 and 12 months after treatment and the differences of two groups were statistically significant (all P<0.05). The serum uric acid in experimental group was significantly lower than that of control group (P<0.05). At 1, 3, 6 and 12 months after treatment, the standard-reaching rate of serum uric acid in the experimental group was significantly higher than that of the control group (all P<0.05). The decrease of residual estimated glomerular filtration rate (eGFR) and residual renal urea clearance index (Kt/V) in the experimental group were significantly lower than those in the control group at 12 months after treatment (all P<0.05). During the follow-up, the incidence of adverse reactions in the experimental group was 9.09% (5/55). Conclusions: Febuxostat can effectively treat PD patients with hyperuricemia and has a high safety profile. Moreover, it may delay the loss of residual renal function.

Flow Pattern Identification of Oil-Water Two-Phase Flow Based on SVM Using Ultrasonic Testing Method

A flow pattern identification method combining ultrasonic transmission attenuation with an ultrasonic reflection echo is proposed for oil-water two-phase flow in horizontal pipelines. Based on the finite element method, two-dimensional geometric simulation models of typical oil-water two-phase flow patterns are established, using multiphysics coupling simulation technology. An ultrasonic transducer test system of a horizontal pipeline with an inner 50 mm diameter was built, and flow pattern simulation experiments of oil-water two-phase flow were carried out in the tested field area. The simulation results show that the ultrasonic attenuation coefficient is extracted to identify the W/O&O/W dispersion flow using the ultrasonic transmission attenuation method, and the identification accuracy is 100%. By comparison, using the ultrasonic reflection echo method, the echo duration is extracted as an input feature vector of support vector machine (SVM), and the identification accuracy of the stratified flow and dispersed flow is 95.45%. It was proven that the method of the ultrasonic transmission attenuation principle combined with the ultrasonic reflection echo principle can identify oil-water two-phase flow patterns accurately and effectively, which provides a theoretical basis for the flow pattern identification of liquid-liquid multiphase flow.

High temperature induces male sterility via MYB66-MYB4-Casein kinase I signaling in cotton

High temperature (HT) causes male sterility and decreases crop yields. Our previous works have demonstrated that sugar and auxin signaling pathways, Gossypium hirsutum Casein kinase I (GhCKI), and DNA methylation are all involved in HT-induced male sterility in cotton. However, the signaling mechanisms leading to distinct GhCKI expression patterns induced by HT between HT-tolerant and HT-sensitive cotton anthers remain largely unknown. Here, we identified a GhCKI promoter (ProGhCKI) region that functions in response to HT in anthers and found the transcription factor GhMYB4 binds to this region to act as an upstream positive regulator of GhCKI. In the tapetum of early-stage cotton anthers, upregulated expression of GhMYB4 under HT and overexpressed GhMYB4 under normal temperature both led to severe male sterility phenotypes, coupled with enhanced expression of GhCKI. We also found that GhMYB4 interacts with GhMYB66 to form a heterodimer to enhance its binding to ProGhCKI. However, GhMYB66 showed an expression pattern similar to GhMYB4 under HT but did not directly bind to ProGhCKI. Furthermore, HT reduced siRNA-mediated CHH DNA methylations in the GhMYB4 promoter, which enhanced the expression of GhMYB4 in tetrad stage anthers and promoted the formation of the GhMYB4/GhMYB66 heterodimer, which in turn elevated the transcription of GhCKI in the tapetum, leading to male sterility. Overall, we shed light on the GhMYB66-GhMYB4-GhCKI regulatory pathway in response to HT in cotton anthers.

Factors associated with mood disorders and the efficacy of the targeted treatment of functional dyspepsia: A randomized clinical trial

Background

Patients with functional dyspepsia (FD) are often accompanied by mood disorders (MDs). This study aimed to identify factors associated with MDs in patients with FD and evaluate the efficacy of targeted treatment plans.

Methods

Relevant scales were used to assess MDs. Patients with FD having MDs and acid reflux were treated with flupentixol and melitracen (FM) and acid-suppressive therapy (AST) (histamine-2 receptor antagonists (H2RAs) (group A) or proton pump inhibitors (PPIs) (group B)), and those without acid reflux (group C) did not receive AST. Patients with FD without MDs were randomly administered H2RAs (group D) or PPIs (group E). The primary endpoints were factors associated with MDs and improvement in gastrointestinal (GI) symptoms and MDs in patients with FD.

Results

A total of 362 patients with FD were enrolled in this study. Patients with FD having high GI score and low education were found prone to MDs. At week 2, the remission rate of overall GI symptoms and depression was significantly higher in group B than that in groups A and C [GI: 72.72% (32/44) vs. 47.73% (21/44) and 72.72% (32/44) vs. 38.94% (44/113), all P &lt; 0.05; depression: 72.22% (26/36) vs. 41.67% (15/36) and 72.22% (26/36) vs. 41.57% (37/89), all P &lt; 0.05]. Furthermore, the remission rate of overall GI symptoms was significantly higher in group E than that in group D [60.29% (41/68) vs. 42.65% (29/68), P &lt; 0.05]. At week 8, similar efficacies and adverse reactions were observed in these groups.

Conclusion

The risk factors for MDs were high GI scores and low literacy rates. Thus, targeted treatment (FM+PPIs for patients with MDs; PPIs for patients without MDs) can improve the efficacy of patients with FD.

Clinical trial registration

www.chictr.org.cn, identifier ChiCTR2100053126.

Environmentally Benign and User-Friendly In Situ Generation of Nitrile Imines from Hydrazones for 1,3-Dipolar Cycloaddition

Nitrile imines are highly reactive and versatile dipoles and conventionally generated in situ from unstable hydrazonyl halides under basic conditions. Herein, we report the first green and user-friendly protocol for in situ generation of nitrile imines from Oxone-KBr oxidation of hydrazones and base-promoted dehydrobromination. The nitrile imines were demonstrated for 1,3-dipolar cycloaddition with various dipolarophiles, including alkene and alkyne groups. With its green nature, ease of operation, and air and moisture tolerance, we expect our method will find wide applications in organic synthesis.

Brain-activation-based individual identification reveals individually unique activation patterns elicited by pain and touch

Pain is subjective and perceived differently in different people. However, individual differences in pain-elicited brain activations are largely overlooked and often discarded as noises. Here, we used a brain-activation-based individual identification procedure to investigate the uniqueness of the activation patterns within the whole brain or brain regions elicited by nociceptive (laser) and tactile (electrical) stimuli in each of 62 healthy participants. Specifically, brain activation patterns were used as "fingerprints" to identify each individual participant within and across sensory modalities, and individual identification accuracy was calculated to measure each individual's identifiability. We found that individual participants could be successfully identified using their brain activation patterns elicited by nociceptive stimuli, tactile stimuli, or even across modalities. However, different participants had different identifiability; importantly, the within-pain, but not within-touch or cross-modality, individual identifiability obtained from three brain regions (i.e., the left superior frontal gyrus, the middle temporal gyrus and the insular gyrus) were inversely correlated with the scores of Pain Vigilance and Awareness Questionnaire (i.e., how a person is alerted to pain) across participants. These results suggest that each individual has a unique pattern of brain responses to nociceptive stimuli which contains both modality-nonspecific and pain-specific information and may be associated with pain-related behaviors shaped by his/her own personal experiences and highlight the importance of a transition from group-level to individual-level characterization of brain activity in neuroimaging studies.

Natural Killer Cells Induce CD8+ T Cell Dysfunction via Galectin-9/TIM-3 in Chronic Hepatitis B Virus Infection

The antiviral response of natural killer (NK) cells and CD8⁺ T cells is weak in patients with chronic hepatitis B (CHB) infection. However, the specific characteristics of these cells and the association between NK cells and CD8⁺ T cell dysfunction is not well known. In this study, higher galectin-9 (Gal-9) expression was observed in circulating NK cells from CHB patients than from healthy controls and was found to contribute to NK cell dysfunction. In addition, circulating CD8⁺ T cells showed obvious dysfunction and overexpressed TIM-3, the natural receptor of Gal-9, during active CHB infection. Gal-9⁺ and Gal-9^- NK cells from active CHB patients were sorted and cocultured with autologous CD8⁺ T cells. The proportion of tetramer⁺CD8⁺ T cells and the cytokines production of CD8⁺ T cells were lower after cocultivation with Gal-9⁺ than with Gal-9^- NK cells. We showed that in vitro depletion of NK cells increased circulating hepatitis B virus (HBV)-specific CD8⁺ T cell responses in patients with active CHB infection. Because Gal-9 is increased in the serum of CHB patients, CD8⁺ T cells were sorted and cultured with exogenous Gal-9, resulting in lower IFN-γ, TNF-α, CD107a, and granzyme B levels, decreased expression of the activation receptor CD69, increased expression of TIM-3, and a high percentage of early apoptotic CD8⁺ T cells. Blocking Gal-9 or TIM-3 in vitro in a culture of peripheral blood mononuclear cells (PBMCs) stimulated with HBV peptide from active CHB patients restored CD8⁺ T cell function. However, blocking Gal-9 in vitro after removal of NK cells from PBMCs did not rescue CD8⁺ T cells exhaustion. Furthermore, NK and CD8⁺ T cells from active CHB patients were sorted and cocultured in vitro, and the exhaustion of CD8⁺ T cells were alleviated after blocking Gal-9 or TIM-3. In summary, overexpression of Gal-9 on NK cells, which interacts with TIM-3⁺CD8⁺ T cells and likely contributes to antiviral CD8⁺ T cell dysfunction, may be a potential target for the treatment of CHB patients.

Genome-Wide Identification and Characterization of Growth Regulatory Factor Family Genes in Medicago

Growth Regulatory Factors (GRF) are plant-specific transcription factors that play critical roles in plant growth and development as well as plant tolerance against stress. In this study, a total of 16 GRF genes were identified from the genomes of Medicago truncatula and Medicago sativa. Multiple sequence alignment analysis showed that all these members contain conserved QLQ and WRC domains. Phylogenetic analysis suggested that these GRF proteins could be classified into five clusters. The GRF genes showed similar exon–intron organizations and similar architectures in their conserved motifs. Many stress-related cis-acting elements were found in their promoter region, and most of them were related to drought and defense response. In addition, analyses on microarray and transcriptome data indicated that these GRF genes exhibited distinct expression patterns in various tissues or in response to drought and salt treatments. In particular, qPCR results showed that the expression levels of gene pairs MtGRF2–MsGRF2 and MtGRF6–MsGRF6 were significantly increased under NaCl and mannitol treatments, indicating that they are most likely involved in salt and drought stress tolerance. Collectively, our study is valuable for further investigation on the function of GRF genes in Medicago and for the exploration of GRF genes in the molecular breeding of highly resistant M. sativa.

[Research advances in transmission dynamic models on hand, foot, and mouth disease]

Hand, foot, and mouth disease (HFMD) is a common childhood infectious disease caused by various enteroviruses. China has the most significant number of reported cases and deaths of HFMD over the globe. Understanding the epidemic laws of HFMD can provide a scientific basis for designing prevention and control measures. The dynamic transmission models focus on the transmission mechanism of infectious diseases. They can simulate the actual situation to study the epidemic rules of diseases by adding, deleting, and subdividing compartments. More researchers have paid attention to dynamic models because of their high flexibility. To carry out the dynamic model of the HFMD research more effectively, a comprehensive understanding of related research progress in this field is deeply needed. In this paper, based on various researchers' different research purposes of dynamic models, the research progress was classified and summarized, providing meaningful guidance for model construction methods and future research directions and references for dynamic modeling of other models of infectious diseases. It was found that most studies used the SIR dynamic model or its extended model (such as the SEIR model), and few studies contained a complex factor compartment. Some important epidemiological parameters (such as R₀) were obtained by studying the HFMD cases in a specific region, simulating different intervention scenarios to evaluate the effect of measures, or revealing the future trend by model prediction. However, there is no dynamic model simultaneously considering age structure, population moving, seasonality and periodicity, and vaccination.

Histone ubiquitination controls organ size in cotton (Gossypium hirsutum)

Ubiquitination plays a vital role in modifying protein activity and destiny. Ub-conjugating enzyme E2 is one of the enzymes that participates in this precise process. There are at least 169 E2 proteins in the allotetraploid cotton (Gossypium hirsutum), but their function remains unknown. Here we identify an E2 gene GhUBC2L and show its positive role in cell proliferation and expansion. Complete knock-down of GhUBC2L in cotton resulted in retarded growth and reduced organ size. Conversely, overexpression of GhUBC2L promoted cotton growth, generating enlarged organs in size. Monoubiquitination of H2A and H2B was strongly impaired in GhUBC2L-suppressed cotton but slightly enhanced in GhUBC2L-overexpressed plant. GhUbox8, a U-box type E3 ligase protein, was found to interact with GhUBC2L both in vivo and in vitro, indicating their synergistical function in protein ubiquitination. Furthermore, GhUbox8 was shown to interact with a series of histone proteins, including histone H2A and H2B, indicating its potential monoubiquitination on H2A and H2B. Expression of genes relating to cell cycle and organ development were altered when the expression of GhUBC2L was changed. Our results show that GhUBC2L modulates histone monoubiquitination synergistically with GhUbox8 to regulate the expression of genes involved in organ development and cell cycle, thus controlling organ size in cotton. This research provides new insights into the role of protein ubiquitination in organ size control. Histone monoubiquitination plays an important role in plant development. Here, we identified an E2 enzyme GhUBC2L that modulates histone monoubiquitination synergistically with an E3 ligase GhUbox8 to mediate organ size control in cotton.

Observation of Voriconazole in the Treatment of Liver Failure Complicated With Invasive Pulmonary Fungal Infection Induced by Chinese Patent Medicine in Teenagers: 2 Case Reports

Background: Drug-induced liver injury (DILI) caused by Chinese patent medicines is increasing in China. The incidence of invasive fungal infections (IFIs) is increasing due to the suppression of the immune function in greater numbers of patients. Invasive procedures such as deep vein catheterization and the use of glucocorticoids are also predisposing factors to IFIs. The clinical presentation of IFI in teenagers is often atypical, challenging to diagnose, difficult to treat, and associated with a high fatality rate. Case presentation: Herein, we report 2 teenagers with liver failure after receiving oral Chinese patent medicines. Case 1 was a 14-year-old boy who presented with subacute liver failure who had been administered a Chinese patent medicine that included acetaminophen. Administration of glucocorticoids and non-bioartificial liver treatment improved his condition. Subsequently, invasive pulmonary Aspergillus (IPA) was diagnosed and was successfully treated with voriconazole for 85 days. Case 2 was a 17-year-old girl who presented with acute liver failure after taking the Chinese patent medicine QubaiBabuqi tablets for vitiligo. Chest computed tomography (CT) revealed multiple pulmonary nodules with an intermittent low-grade fever, and she was diagnosed with IPA. She was initially treated with caspofungin (23 days) and then voriconazole (406 days) for 429 days. Her liver function returned to normal, and lung lesions were absorbed in 2 patients. At the same time, two to three histopathological examinations of the liver biopsy showed that the drug-induced autoimmune-like phenomena could be improved by glucocorticoid therapy. Conclusion: To the best of our knowledge, this is the first report of the successful treatment of 2 cases of liver failure (Child-Pugh class C) caused by Chinese patent medicines complicated with IPA in teenagers. Drug-induced autoimmune-like phenomena could be improved by glucocorticoid therapy.

Short-term outcomes of intracorporeal and extracorporeal anastomosis in robotic right colectomy: a systematic review and meta-analysis

Ileocolic anastomosis is performed via extracorporeal or intracorporeal techniques in robotic right hemicolectomy. The aim of this meta-analysis was to compare the short-term outcomes of intracorporeal anastomosis (IA) and extracorporeal anastomosis (EA) for robotic right colectomy. The EMBASE, PubMed, and Cochrane Library databases were searched systematically (from inception until March 1, 2020) for randomized and non-randomized control trials reporting the short-term outcomes of IA and EA for robotic right colectomy. Five observational cohort studies involving 585 participants were included in our meta-analysis. Compared to the EA group, the IA group showed significantly longer operation time [weighted mean difference (WMD): 28.88, 95% confidence interval (CI) 13.88-43.89, p = 0.0002], lower rate of anastomotic leak (odds ratio: 0.26, 95% CI 0.08-0.85, p = 0.03), and shorter time to first flatus (WMD: - 0.57, 95% CI - 0.95 to 0.19, p = 0.003). However, pooled results revealed no difference in blood loss, complications, wound infection, incisional hernia, length of incision, and hospital stay between the IA and EA groups (p < 0.05). This meta-analysis indicated that IA was superior to EA in terms of anastomotic leak and time to first flatus, but inferior in terms of operation time. Large-scale, multicenter, randomized studies are needed to confirm our findings.

Functional MRI evidence for primary motor cortex plasticity contributes to the disease's severity and prognosis of cervical spondylotic myelopathy patients

OBJECTIVE

To investigate the brain mechanism of non-correspondence between diseases severity and compression degree of the spinal cord in cervical spondylotic myelopathy (CSM) patients and to test the utility of brain imaging biomarkers for predicting prognosis of CSM.

METHODS

We calculated voxel-wise zALFF from 54 CSM patients and 50 healthy controls using resting-state fMRI data. In analysis 1, we identified the brain regions exhibited significant differences of zALFF between CSM patients and healthy controls. In analyses 2 through 3, we investigated the zALFF differences between light-symptom CSM patients and severe-symptom CSM patients while carefully matching the degree of compression between these two groups. In analysis 4, we tested the utility of zALFF within the primary motor cortex (M1) for predicting the prognosis of CSM.

RESULTS

We found that (1) compared with the healthy controls, CSM patients exhibited higher ALFF within left M1, bilateral superior frontal gyrus, and lower zALFF within right precuneus and calcarine, suggesting altered brain neural activity in CSM patients; (2) after matching the compression degree, the CSM patients with more severe clinical symptoms exhibited higher zALFF within M1, indicating cortical function contributes to disease's severity of CSM; (3) taking the M1 zALFF as features in the prognosis prediction model improves the prediction accuracy, indicating that the M1 zALFF provide additional value for predicting the prognosis of CSM patients following decompression surgery.

CONCLUSION

The functional state of M1 contributes to the disease's severity of CSM and can provide complementary information for predicting the prognosis of CSM following decompression surgery.

KEY POINTS

• Cervical spondylotic myelopathy (CSM) patients exhibited increased zALFF within the primary motor cortex (M1), bilateral superior frontal gyrus, and decreased zALFF within the right precuneus and calcarine. • After matching the compression degree, the CSM patients with more severe clinical symptoms exhibited higher zALFF within M1, indicating cortical function contributes to disease severity of CSM. • zALFF within M1 provided additional value for predicting the prognosis of CSM patients.

Experimental Study of the Dynamic Characteristics of a New Antidrainage Subgrade Structure for High-Speed Railways in Diatomaceous Earth Areas

The experience needed to carry out engineering and construction in diatomaceous earth areas is currently lacking. This project studies the new Hang Shaotai high-speed railway passing through a diatomaceous earth area in Shengzhou, Zhejiang Province, and analyzes the hydrological and mechanical properties of diatomaceous earth on the basis of a field survey and laboratory. Moreover, a new antidrainage subgrade structure was proposed to address the rainy local environment, and field excitation tests were performed to verify the antidrainage performance and stability of the new subgrade structure. Finally, the dynamic characteristics and deformation of the diatomaceous earth roadbed were examined. The hydrophysical properties of diatomaceous earth in the area are extremely poor, and the disintegration resistance index ranges from 3.1% to 9.0%. The antidrainage subgrade structure has good water resistance and stability under dynamic loading while submerged in water. After 700,000 loading cycles, the dynamic stress and vibration acceleration of the surface of the subgrade bed stabilized at approximately 6.37 kPa and 0.94 m/s², respectively. When the number of excitations reached 2 million, the settlement of the diatomaceous earth foundation was 0.08 mm, and there was basically negligible postwork settlement of the diatomaceous earth foundation. These results provide new insights for engineering construction in diatomaceous earth areas.