Discerning Robert Frost's Life Philosophy from Some of His Poems——Roaming on the Margin of Retreat and Regress

As a giant figure of American literature,Robert Frost has been receiving world-wide concerns and studies in literati.On retreat and regress,it intends to discern Robert Frost's life philosophy——"roaming on the margin of retreat and regress"from some of his poems from humanism approach.

The dominant driving force for supercontinent breakup: Plume push or subduction retreat?

Understanding the dominant force responsible for supercontinent breakup is crucial for establishing Earth＇s geodynamic evolution that includes supercontinent cycles and plate tectonics. Conventionally,two forces have been considered： the push by mantle plumes from the sub-continental mantle which is called the active force for breakup, and the dragging force from oceanic subduction retreat which is called the passive force for breakup. However, the relative importance of these two forces is unclear. Here we model the supercontinent breakup coupled with global mantle convection in order to address this question. Our global model features a spherical harmonic degree-2 structure, which includes a major subduction girdle and two large upwelling（superplume） systems. Based on this global mantle structure,we examine the distribution of extensional stress applied to the supercontinent by both subsupercontinent mantle upwellings and subduction retreat at the supercontinent peripheral. Our results show that：（1） at the center half of the supercontinent, plume push stress is ～3 times larger than the stress induced by subduction retreat;（2） an average hot anomaly of no higher than 50 K beneath the supercontinent can produce a push force strong enough to cause the initialization of supercontinent breakup;（3） the extensional stress induced by subduction retreat concentrates on a ～600 km wide zone on the boundary of the supercontinent, but has far less impact to the interior of the supercontinent. We therefore conclude that although circum-supercontinent subduction retreat assists supercontinent breakup, sub-supercontinent mantle upwelling is the essential force.

Subsidence over room and pillar retreat mining in a low coal seam

The objective of this paper is to study the behavior of a low thick and low depth coal seam and the overburden rock mass. The mining method is room and pillar in retreat and partial pillar recovery. The excavation method is conventional drill and blast because of the small production. The partial pillar recovery is about 30% of the previous pillar size, 7 m × 7 m. The roof displacement was monitored during retreat operation; the surface movement was also monitored. The effect of the blasting vibration on the final pillar strength had been considered. Due to blasting, the pillar reduced about 20%. The consequence is more pillar deformation and roof vertical displacement. The pillar retreat and ground movement were simulated in a three-dimensional numerical model. This model was created to predict the surface subsidence and compare to the subsidence measured. This study showed that the remaining pillar and low seam reduce the subsidence that was predicted with conventional methods.

Growth of the Sayram Lake and retreat of its water-supplying glaciers in the Tianshan Mountains from 1972 to 2011

Inland lakes and alpine glaciers are important constituents of water resources in arid and semiarid regions. Understanding their variations is critical for both an accurate evaluation of the dynamic changes of water resources and the retrieval of climatic information. On the basis of earlier researches, this study investigated the growth of the Sayram Lake and the retreat of its water-supplying glaciers in the Tianshan Mountains using long-term sequenced remote sensing images. Our results show that over the past 40 years, the surface area and the water level of the lake has increased by 12.0±0.3 km2 and 2.8 m, respectively, and the area of its water-supplying glaciers has decreased continuously since the early 1970s with a total reduction of about–2.13±0.03 km2. Our study has indicative significance to the research of regional climate change.

ONSET AND RETREAT DATES OF THE SOUTH CHINA SEA SUMMER MONSOON AND THEIR RELATIONSHIPS WITH THE MONSOON INTENSITY IN THE CONTEXT OF CLIMATE WARMING

Global gridded daily mean data from the NCEP/NCAR Reanalysis(1948-2012) are used to obtain the onset date,retreat date and duration time series of the South China Sea summer monsoon(SCSSM) for the past 65 years.The summer monsoon onset(retreat) date is defined as the time when the mean zonal wind at 850 hPa shifts steadily from easterly(westerly) to westerly(easterly) and the pseudo-equivalent potential temperature at the same level remains steady at greater than 335 K(less than 335 K) in the South China Sea area[110-120°E(10-20°N)].The clockwise vortex of the equatorial Indian Ocean region,together with the cross-equatorial flow and the subtropical high,plays a decisive role in the burst of the SCSSM.The onset date of the SCSSM is closely related to its intensity.With late(early) onset of the summer monsoon,its intensity is relatively strong(weak),and the zonal wind undergoes an early(late) abrupt change in the upper troposphere.Climate warming significantly affects the onset and retreat dates of the SCSSM and its intensity.With climate warming,the number of early-onset(-retreat) years of the SCSSM is clearly greater(less),and the SCSSM is clearly weakened.

Quadruple therapy with furazolidone for retreatment in patients with peptic ulcer disease

AIM: To establish the efficacy and safety of a 7-d therapeutic regimen using omeprazole,bismuth subcitrate,furazolidone and amoxicillin in patients with peptic ulcer disease who had been previously treated with other therapeutic regimens without success.METHODS: Open cohort study which included patients with peptic ulcer who had previously been treated unsuccessfully with one or more eradication regimens.The therapeutic regimen consisted of 20 mg omeprazole,240 mg colloidal bismuth subcitrate,1000 mg amoxicillin,and 200 mg furazolidone,taken twice a day for 7 d.Patients were considered as eradicated when samples taken from the gastric antrum and corpus 12 wk after the end of treatment were negative for Helicobacter pylori (H pylori) (rapid urease test and histology).Safety was determined by the presence of adverse effects.RESULTS: Fifty-one patients were enrolled.The eradication rate was 68.8% (31/45).Adverse effects were reported by 31.4% of the patients,and these were usually considered to be slight or moderate in the majority of the cases.Three patients had to withdraw from the treatment due to the presence of severe adverse effects.CONCLUSION: The association of bismuth,furazolidone,amoxicillin and a proton-pump inhibitor is a valuable alternative for patients who failed to respond to other eradication regimens.It is an effective,cheap and safe option for salvage therapy of positive patients.

Regional differences in global glacier retreat from 1980 to 2015

Global warming triggers shrinking and thinning of glaciers worldwide,with potentially severe implications for human society.However,regional differences in glacier retreat and its relationship with climatic characteristics have not been conclusively demonstrated.In this study,regional changes in global glaciers based on two primary features,area change and mass balance,were investigated on the basis of data collected from published research on glacier changes.Results show that during the period 1980—2015,the rate of global glacier area shrinkage was 0.18%per year and that of global glacier mass loss was 0.25 m w.e.per year.Retreat of glaciers located at low and middle latitudes was characterized by severe area shrinkage and mass loss.Correspondingly,in the Arctic,deglaciation was characterized by ice thinning due to a low area reduction but relatively high mass loss rate.However,glaciers in high southern latitudes were in a relatively stable status.High Mountain Asia exhibited the lowest rate of area shrinkage and mass loss among glaciers located at low and middle latitudes,and a slower rate of mass loss compared with the global average.Glaciers in the Tropical Andes exhibited the fastest rate of glacier area shrinkage(—1.6%per year),whereas Antarctic and Subantarctic glaciers showed the lowest rate(—0.11%per year).For mass balance,the most negative occurred at Southern Andes(—0.81 m w.e.per year),followed by Alaska(-0.74 m w.e.per year).Only the Antarctic and Subantarctic experienced small mass gain(0.04 m w.e.per year).High levels of correlation are found between the rates of glacier retreat and annual average temperature and annual total precipitation instead of their trends.The variability of the surface climate conditions in the glacier environment plays a key role in driving these regional differences in global glacier retreat.

Design concerns of room and pillar retreat panels

Why do some room and pillar retreat panels encounter abnormal conditions？ What factors deserve the most consideration during the planning and execution phases of mining and what can be done to mitigate those abnormal conditions when they are encountered7 To help answer these questions, and to determine some of the relevant factors influencing the conditions of room and pillar （R ＆ P） retreat min- ing entries, four consecutive R ＆ P retreat panels were evaluated. This evaluation was intended to rein- force the influence of topographic changes, depth of cover, multiple-seam interactions, geological conditions, and mining geometry. This paper details observations were made in four consecutive R ＆ P retreat panels and the data were collected from an instrumentation site during retreat mining. The pri- mary focus was on the differences observed among the four panels and within the panels themselves. The instrumentation study was initially planned to evaluate the interactions between primary and secondary support, but produced rather interesting results relating to the loading encountered under the current mining conditions. In addition to the obse^ation and ｜ll^trumentation, numerical modeling was per- formed to evaluate the stress condi~!ons. Both the LaModel 3.0 and Rocscience Phase 2 programs were used to evaluate these four panels, The results of both models indicated a drastic reduction in the vertical stresses experienced in these panels due to the full extraction mining in overlying seams when compared to the full overburden load. Both models showed a higher level of stress associated with the outside entries of the panels. These results agree quite well with the observations and instrumentation studies performed at the mine. These efforts provided two overarching conclusions concerning R ＆ P retreat mine planning and execution. The first was that there are four areas that should not be overlooked during R ＆ P retreat mining： topographic relief, multiple^seaPa stress relief, stress concentrations near the gob edge, and geologic changes in the immediate roof. The second is that in order to successfully retreat an R ＆ P panel, a three-phased approach to the design and analysis of the panel should be conducted： the planning phase, evaluation phase, and monitoring phase.

Stability assessment of rock surrounding an I-beam supported retreating roadway

The installation of a back-wall guard-board is the key to successfully supporting underground retreating roadways in coal mines. Based on the coordinate support principle, and using an I-shaped steel support for the surrounding rock, a mechanical model was developed for the stability of the roadway support and surrounding rock. Analysis of the bearing capacity of the roof back-wall guard-board and modelling of the equations for the maximum deflection and the maximum compressive stress of the top and side beams of the I-shaped steel support were undertaken. Simultaneously, the model was used to calculate and analyse the stability of the top and side beams of the I-shaped steel support structure and analyse the criteria for their stability. The results provide a reliable theoretical basis for the judgment of the stability of the surrounding rock and support structure. The theoretical evaluation results are consistent with field data. Finally, the key support parameters of the top and side beams of the I-shaped steel support structure and the variation of the maximum deflection and the maximum compressive stress as affected by the influence of the guard-board length were investigated. It is concluded that, as the back-board length increases, the maximum compressive stress in the top beam of the I-shaped steel support increases while the compressive stress in the side beam decreases. The results show that the accuracy of judgment of the stability of a supported retreating roadway is improved, providing guidance for the design of such typical I-shaped steel support and back-board structures.

Assessment of Retreatment Tuberculosis Cases amongst All Tuberculosis Cases Notification in District Swat 2015-2017: A Retrospective Cohort Review

Retreatment Tuberculosis (TB) has long been a neglected area in global TB control. To determine the notification of re-treatment Tuberculosis TB cases among all enrolled TB patients, we conducted a retrospective cohort review of routine program data from 2015-2017. A total of 8663 tuberculosis cases (all new and old forms) were registered at the study site. Of these, 1916 (22%) were pulmonary bacteriological confirmed;3498 (40.37%) were pulmonary clinical diagnosed and 3396 (39.20%) were clinically or bacteriological confirmed extra-pulmonary tuberculosis cases. Retreatment cases trend was found to be increased from 1% in 2015 to 1.6% in 2017. Majority of re-treatment cases were in the age group 18 - 43 years and only 7 patients were under the age of 15 years. This concludes that notification of re-treatment cases is very low among all enrolled TB patients and this could be possibly due to the fact that most of the re-treatment cases were registered as new cases or misdiagnosed. There is need and space to increase retreatment cases. Most of the re-treatment cases were usually converted to MDR-TB (Multi-Drug Resistant Tuberculosis) as noted in PMDT (Programmatic management of Drugs resistant tuberculosis) site. Therefore, proper history and diagnosis should be encouraged at the time of case notification.

Ground control monitoring of retreat room–and–pillar mine in Central Appalachia

In order to study pillar and overburden response to retreat mining, a ground control program was conducted at a Central Appalachian Mine. The program consisted of several monitoring methods including a seismic monitoring system, borehole pressure cells in the pillars, and time-lapse photogrammetry of the pillar ribs. Two parallel geophone arrays were installed, one on each side of the panel with the sensors mounted 3 m into the roof. A total of fourteen geophones recorded more than 5000 events during the panel retreat. A MIDAS datalogger was used to record pressure from borehole pressure cells(BPCs)located in two adjacent pillars that were not mined during retreat. A series of photographs were taken of the pillars that had the BPCs as the face approached so that deformation of the entire rib could be monitored using photogrammetry. Results showed that pillar stability and cave development were as expected. The BPCs showed an increase in loading when the face was 115 m inby and a clear onset of the forward abutment at 30 m. The photogrammetry results displayed pillar deformation corresponding to the increased loading. The microseismic monitoring results showed the overburden caving inby the face, again as expected. The significance of these results lies in two points,(1) we can quantify the safe manner in which this mine is conducting retreating operations, and(2) we can use volumetric technologies(photogrammetry and microseismic) to monitor entire volumes of the mine in addition to the traditional point-location geotechnical measurements(BPCs).

Impact of ribavirin dose on retreatment of chronic hepatitis C patients

AIM: To study the efficacy and factors associated with a sustained virological response (SVR) in chronic hepatitis C (CHC) relapsing patients. METHODS: Out of 1228 CHC patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV), 165 (13%) had a relapse. Among these, 62 patients were retreated with PEG-IFN-2a or-2b and RBV. Clinical, biological, virological and histological data were collected. Initial doses and treatment modifications were recorded. The efficacy of retreatment and predictive factors for SVR were analyzed. RESULTS: An SVR was achieved in 42% of patients. SVR was higher in young (< 50 years) (61%) than old patients (27%) (P = 0.007), and in genotype 2 or 3 (57%) than in genotype 1 or 4 (28%) patients (P = 0.023). Prolonging therapy for at least 24 wk more than the previous course was associated with higher SVR rates (53% vs 28%, P = 0.04). Also, a better SVR rate was observed with RBV dose/body weight > 15.2 mg/kg per day (70% vs 35%, P = 0.04). In logistic regression, predictors of a response were age (P = 0.018), genotype (P = 0.048) and initial RBV dose/body weight (P = 0.022). None of the patients without a complete early virological response achieved an SVR (negative predictive value = 100%). CONCLUSION: Retreatment with PEG-IFN/RBV is effective in genotype 2 or 3 relapsers, especially in young patients. A high dose of RBV seems to be important for the retreatment response.

Heterogeneity of immune control in chronic hepatitis B virus infection:Clinical implications on immunity with interferon-αtreatment and retreatment

Hepatitis B virus(HBV)infection is a global public health issue.Interferon-α(IFN-α)treatment has been used to treat hepatitis B for over 20 years,but fewer than 5%of Asians receiving IFN-αtreatment achieve functional cure.Thus,IFN-αretreatment has been introduced to enhance antiviral function.In recent years,immune-related studies have found that the complex interactions between immune cells and cytokines could modulate immune response networks,including both innate and adaptive immunity,triggering immune responses that control HBV replication.However,heterogeneity of the immune system to control HBV infection,particularly HBV-specific CD8^(+)T cell heterogeneity,has consequential effects on T cell-based immunotherapy for treating HBV infection.Altogether,the host’s genetic variants,negative-feedback regulators and HBV components affecting the immune system's ability to control HBV.In this study,we reviewed the literature on potential immune mechanisms affecting the immune control of HBV and the clinical effects of IFN-αtreatment and retreatment.

Significance of glacio-morphological factors in glacier retreat：a case study of part of Chenab basin,Himalaya

A study has been carried out in part of Chenab basin,Himalaya to understand the relationship between glacio-morphological factors and change in glacial area. Initially change in areal extent of glaciers was derived for two time frames(1962-2001/02 and 2001/02-2010/11). The study comprised of 324 glaciers for the monitoring period of 1962-2001/02 for,which 11% loss in glacial area was observed. Two hundred and thirty-eight glaciers were further monitored between 2001/02 and 2010/11. These glaciers showed an area loss of 1.1%. The annual deglaciation has been found to be higher during the period of 1962-2001/02 compared to 2001/02-2010/11. The spatial and temporal variability in deglaciation was also addressed usingglacio-morphic parameters. Area,length,percentage of debris cover,and various elevation parameters of glaciers were observed to have significant controls on relationships to the rate of glacial shrinkage. Largerarea and longer glaciers show a lower percentage of retreat than smaller and shorter ones. Moreover,glaciers located at lower altitudes and having gentle slopes show more area retreat. The results of area retreat in debris covered and debris free glaciers supports that the glaciers covered by debris retard ice melting at some extent. 158 glaciers were observed having no debris cover,and these exhibit 14% of loss in surface area. In glaciers having 40% debris cover,8% of deglaciation was observed. The glaciers located below equilibrium line altitude(ELA) have experienced 4.6% of deglaciation for the time frame 2001/02 – 2010/11 whereas it was found to be 1.1% for the glaciers occurring above ELA. However,theorientation of glaciers did not show any considerable influence on glacial change based on hypothesis.

Follow-up Study of Retreatment TB Patients with Sputum Smear and/or Culture Positive Two Years after They were Declared Cured with First-line Anti-TB Drugs in Shandong Province

This study aimed to learn the recurrence rate in the retreatment TB patients with sputum smear and/or culture positive （ss＋ and/or c＋） two years after they were declared cured, and to explore causes of recurrence in order to improve long-time treatment outcome. 5 cities were selected as research locations. Recurrence of TB was judged by chest X-ray examination together with sputum smear and culture examination.

Antarctic Glacial Retreats and the Records of Sea Level Change in Deposits at the North Bank of the Shenzhen Bay,South China

In view of the huge ice cover of 24. 5× 106 km3 in Antarctica, which accounts for over 90 % by volume of the ice body on earth, the movement of Antarctic glaciers is a major control on global sea-level change and climatic fluctuation. As recorded in the Quaternary deposits in King George Island, West Antarctica, three rapid ablations can be recognized at 11000, 9000 and 6100 years ago and the global climate within the past 6000 years is characterized by small-amplitude warm-cold fluctuation. Intertidal deceits at the north bank of the Shenzhen Bay suggest a periodic variation in sea level in about every 670 years over the last 6000 years with low sea levels recorded in the periods of 5500 - 4900, 3900 - 3600, 2400 2200 and 1300 - 1200 years ago. Between these periods the sea level rised for about 80 cm onaverage. The modern warming climate in the last century corresponds with a rise of sea level atthe rate of 2 - 3 mm/a.

The Disintegration of the Middle East Retreating to the ＂Weak Sovereignty Era＂

The Arab Spring in the spring of 2011 soon brought the Middle East into an abyss of chaos, instability, terrorism and civil war. Over the past six years, the Syria conflict in some areas tended to cool down. President Trump reached an agreement with Russian President Putin on building a new ＂conflict relegation zone＂ on July 7, 2017. After three years of hard fighting, Iraq liberated Mosul on July 9, 2017. Full restoration of territorial integrity is just around the comer. ISIS lost Mosul, and was trapped in Racca. Further loss of land and territory is just a matter of time.

Spectrum of Filamentous Fungi from Sputum of Tuberculosis Relapse and Retreatment Patients in Tuberculosis Reference Facilities

Background: Fungal infections represent a significant cause of morbidity and mortality among immunocompromised individuals. Pulmonary fungal infection may be missed or misdiagnosed as tuberculosis (TB) hence complicating management of these patients. The current study reports the spectrum of filamentous fungi isolated from sputum of TB relapse and retreatment cases at selected reference facilities in Kenya. Methods: A total of 340 sputum samples collected during the period of June 2018 to June 2019 were subjected to mycological investigations. The samples were mucolysed and inoculated on sabourauds dextrose agar (SDA) and incubated at 30°C for 7 days and checked daily for fungal growth. Moulds were identified by macroscopic and microscopic morphological features and the species were confirmed by sequencing. Results: The diversity of fungi out of the 340 sputum samples analyzed was as follows;16% (n = 53) were positive for moulds with Aspergillus species being the predominant constituting 68 % (n = 36). Among the Aspergilli, A. flavus and A. niger were the most frequently isolated adding up to 23%, (n = 12) and 15% (n = 8) respectively. Additionally, Paecillomyces variotii (9%, n = 5), Scedosporium aspiospermum (6%, n = 3), Mucor racemosus (8%, n = 4) and Penicillium spp. (9%, n = 5) were also recovered. Conclusion: The isolated fungi represented potential respiratory pathogens that could be responsible for persistent TB like symptoms despite treatment that could be misdiagnosed as relapse requiring treatment. Fungal investigation of all presumptive TB relapse cases should be advocated before treatment. This will reduce unnecessary retreatment, delayed antifungal intervention and unwarranted morbidity and mortality associated with misdiagnosis.

Non-Surgical Endodontic Retreatment of Anterior Tooth with a Large Periapical Lesion and Extruded Guta Percha with 36 Months Follow-Up: A Case Report

Root canal treatment failure depends on many factors. Overfillings, insufficient fillings, missing canals, failure to provide a complete apical plug, and impermeability of coronal restoration are some of them. Failed root canal treatment may not always manifest itself immediately after treatment. Sometimes, root canal treatments, which have not been done well, can manifest themselves with extensive lesions and severe pain in the apical after a long time. Apical resection may be considered as a solution in lesions that are too large to be treated, but retreatment without surgery should be attempted beforehand. Thus, the patient may have recovered from unnecessary surgical procedures and treated with a more conservative method. This case presents the non-surgical retreatment of a left lateral tooth with a large periapical lesion with extruded gutta percha followed by a 36-month follow-up.

Enhanced Biohydrogen Production by Accelerating the Hydrolysis of Macromolecular Components of Waste Activated Sludge Using TiO₂Photocatalysis as a Pretreatment

The effects of TiO2 photocatalysis on the hydrolysis of protein of waste activated sludge (WAS) and its biodegradability were investigated in this study. After 12-h UV irradiation, the removal ratio of protein by TiO2 photocatalysis reached 98.1%. The optimal condition for photocatalytic degradation of protein is TiO2 dosage of 5.0 mg·L–1 under 2.4 w·m–2 UV light irradiation. TiO2 photocatalysis in comparison with other pretreatments obviously accelerated the hydrolysis of WAS and improved the conversion of total COD (tCOD) to soluble COD (sCOD). The sCOD/tCOD ratio of WAS pretreated by TiO2 photocatalysis, UV photolysis and TiO2 adsorption and that of the control were 92.8%, 32.5%, 18.0% and 16.6%, respectively. TiO2 photocatalytic pretreatment accelerated the biohydrogen production from 10-fold diluted WAS. The bioreactors containing UV photolysis and TiO2 adsorption pretreated WASs and the control reactor require 0.5-d, 0.9-d and 0.7-d start-up period for biohydrogen production, respectively. While the bioreactor containing TiO2 photocatalysis pretreated WAS obtained a hydrogen yield of 0.5 mL-H2/g-VS merely after 0.5-d mesophilic fermentation. The cumulative biohydrogen production from TiO2 photocatalysis pretreated WAS during 4-d mesophilic fermentation reached 11.7 mL-H2/g-VS, which was 1.2 times higher than that from the control. TiO2 photocatalytic pretreatment enhanced the biohydrogen production from WAS via accelerating the hydrolysis of its macromolecular components to smaller molecule weight hydrolysates.