Short Period Research Articles

Pseudo-Velocity Response Spectrum to Velocity Response Spectrum Conversion Model

ABSTRACT Velocity response spectrum (SV) plays a critical role in the seismic design of structures equipped with velocity-dependent dampers. Often, the SV is approximated using the pseudo-velocity response spectrum (PSV), because of the lack of information on the SV in seismic codes. As indicated in the existing literature, the error of this approximation is significant for short and long periods, and therefore, researchers have started to develop PSV to SV conversion models for obtaining SV more accurately. Recent studies discovered that the relationship between the PSV and SV is affected not only by structural parameters, but also by magnitude, distance, and site class. However, models for converting PSV to SV including magnitude, distance, and site class as input parameters have not been developed. To this end, a PSV to SV conversion model including magnitude, distance, and site class is proposed in this study based on a large number of real ground motion records (16,660 horizontal acceleration time histories) selected from the Japan Strong Motion Network. Furthermore, since the magnitude and distance are not specified in the seismic design, a response-spectrum-shape factor, s, is discussed to reflect the influences of magnitude and distance. Accordingly, an SV/PSV model incorporating s is established. The proposed models show better accuracy than the existing models for cases with different magnitudes, distances, and site classes.

Heritability Estimates for Growth Traits and Correlation Analysis between Weight and Metamorphosis Rate in the Bullfrog Rana (Aquarana) catesbeiana

Metamorphosis is a crucial process in the life cycle of Rana (Aquarana) catesbeiana. R. catesbeiana tadpoles, in their short larval period, possess a high survival rate and also a highly competitive ability in the amphibious stage. In actual seed production, the economic traits of larval period and metamorphosis rate are used as quantifiable indicators of quality for individuals and populations, respectively. However, studies of these economic traits in larval cultivation and production are still lacking. In this study, we constructed 40 full-sib families of R. catesbeiana and measured the weight and metamorphosis rate of tadpoles at different developmental stages. Subsequently, we calculated the phenotypic and genetic association between weight and metamorphosis rate in tadpoles and assessed the heritability of these two traits. The heritabilities of weight at three developmental stages were all higher than 0.40 and decreased with advancement of the developmental stage; the heritability of the metamorphosis rate was 0.18 ± 0.20, a moderate level. Correlation analysis of weight and metamorphosis rate at each developmental stage in each tadpole family showed that weight at stages 25-I, 25-II, and 25-III was significantly correlated at the phenotypic level but non-significantly at the genetic level. The metamorphosis rate was only moderately associated with stage 25-III weight (0.38, p < 0.05). The results of this study confirm the importance and transportability of tadpole weight in actual seed production and provide basic data and a potentially optimized direction for the selective breeding of high-metamorphosis-rate bullfrogs.

Molten Salt Pump Journal-Bearings Dynamic Characteristics Under Hydrodynamic Lubrication Conditions

Abstract A reliable high-temperature molten salt pump is critical for the development of Fluoride-salt-cooled, High-temperature Reactors (FHRs). By supporting the rotating journal, the appropriate journal bearing can ensure that the high-temperature molten salt pump runs smoothly and efficiently in the high-temperature fluoride salt over a long period of time. However, many bearing candidates served well for only a short period and experienced several issues. Moreover, the alignment of the molten salt pump journal bearings is a key factor for the molten salt pump's long-term steady running. In the long-term operation, a misalignment in the journal bearing can result in vibrations and excessive wear on the bearing surface of the molten salt pump. The journal bearing dynamic characteristics can be used to accurately assess the journal misalignment. Therefore, it is necessary to investigate the detailed journal-bearing dynamic behavior under the high-temperature hydrodynamic fluoride salt lubrication conditions for FHR applications. In this study, a small amplitude vibration is superimposed on a steady-running journal bearing to simulate the molten salt operating conditions. A Fortran 90 code has been written for the journal-bearing dynamic behavior analysis. The code was verified using the numerical data reported in the literature. The code is then employed to predict the dynamic coefficients of high-temperature fluoride salt hydrodynamic lubricated journal-bearing with various Sommerfeld numbers. These journal-bearing dynamic coefficients can be used to provide guidelines in the design of molten salt pumps.

Insights into carbonate environmental conditions in the Chukchi Sea

Abstract. Healthy Arctic marine ecosystems are essential to the food security and sovereignty, culture, and wellbeing of Indigenous Peoples in the Arctic. At the same time, Arctic marine ecosystems are highly susceptible to impacts of climate change and ocean acidification. While increasing ocean and air temperatures and melting sea ice act as direct stressors on the ecosystem, they also indirectly enhance ocean acidification, accelerating the associated changes in the inorganic carbon system. Yet, much is to be learned about the current state and variability of the inorganic carbon system in remote, high-latitude oceans. Here, we present time series (2016–2020) of pH and the partial pressure of carbon dioxide (pCO2) from the northeast Chukchi Sea continental shelf. The Chukchi Ecosystem Observatory includes a suite of subsurface year-round moorings sited amid a biological hotspot that is characterized by high primary productivity and a rich benthic food web that in turn supports coastal Iñupiat, whales, ice seals, walrus (Odobenus rosmarus), and Arctic cod (Boreogadus saida). Our observations suggest that near-bottom waters (33 m depth, 13 m above the seafloor) are a high carbon dioxide and low pH and aragonite saturation state (Ωarag) environment in summer and fall, when organic material from the highly productive summer remineralizes. During this time, Ωarag can be as low as 0.4. In winter, when the site was covered by sea ice, pH was <8 and Ωarag remained undersaturated under the sea ice. There were only two short seasonal periods with relatively higher pH and Ωarag, which we term ocean acidification relaxation events. In spring, high primary production from sea ice algae and phytoplankton blooms led to spikes in pH (pH > 8) and aragonite oversaturation. In late fall, strong wind-driven mixing events that delivered low-CO2 surface water to the shelf also led to events with elevated pH and Ωarag. Given the recent observations of high rates of ocean acidification and a sudden and dramatic shift of the physical, biogeochemical, and ecosystem conditions in the Chukchi Sea, it is possible that the observed extreme conditions at the Chukchi Ecosystem Observatory are deviating from the carbonate conditions to which many species are adapted.

The Transformation of the Ordinariate for Poles in Germany into the Polish Catholic Mission in Germany

Due to the special situation of Poles in Germany after the end of the Second World War and the need to provide them with pastoral care, an Ordinariate for Poles in Germany was established as a personal diocese by a decision of the Holy See on 5 June 1945. In a relatively short period of time and despite very difficult conditions, it was possible to organise effective pastoral structures. The main burden of work rested with the parishes, whose numbers began to dwindle over time as the number of Poles in Germany decreased. In connection with the new legislation on the pastoral care of migrants, in 1976 the former personal diocese for Poles was transformed into the Polish Catholic Mission in Germany. This was also accompanied by a change in the status of the priest in charge of Polish pastoral ministry in Germany. The new structures proved to be adequate for the pastoral challenges that arose later and, as a result, the Polish Catholic Mission in Germany has been able to develop to this day.

State Violence and Pains of Punishment: Experiences of Incarcerated Women in Belarus in the Aftermath of the 2020 Protests

Abstract State violence against Belarusian women involved in protest activities after the fraudulent presidential election in 2020 and onward has been unprecedented in the country’s history. Women’s activism has challenged the patriarchal authoritarian regime, which was ill-prepared to deal with women. However, after a short period of adaptation by the repressive institutions, women became their “special clients.” With reference to gender-sensitive academic research, we investigate diverse forms of state violence against women and analyze how they perceive their experiences of incarceration for political reasons. This article is based on available datasets, a series of nine semi-structured interviews, and insights from participant observation. The research reveals that Belarusian women incarcerated for political reasons fall under the “demanding clients” category: they comprehensively challenge the state-sponsored brutal patriarchy and expect the repressive apparatus to meet their specific needs. These women experience multidimensional physical discomfort and psychological pressure, including targeted offensive and dehumanizing elements. At the same time, incarcerated women do not feel ostracized by society; they share the feeling that their “crimes” are supported by civil society, and they endure the pains of punishment as targeted violence from a state fighting cynically for its own survival.

Trajectory in water scarcity and potential water savings benefits in the Yellow River basin

Water scarcity caused by the mismatched spatiotemporal characteristics of water demand and supply threatens the sustainable development of many countries around the world. The Yellow River is the second largest river in China but suffers from intense human activity and scarce water resources. Most current studies on water scarcity assessment have coarse spatial and temporal resolution or are based over short periods, which precludes our understanding of the long-term trajectories of water scarcity. Moreover, the water savings potential and implications for water scarcity alleviation have not been well understood. Here, we conducted a comprehensive analysis of water scarcity in the Yellow River basin (YRB) during the period 1965–2013 using a survey-based water withdrawal dataset and water availability simulated by a well-validated hydrological model. Our results showed that regional water stress has continuously increased over the past five decades and has exceeded the threshold above which both ecological and socio-economic water resources are unsustainable since the 1990 s. Regions with high water stress were mostly distributed between the Lanzhou and Toudaoguai hydrological stations where large irrigated districts occur. There were 30.1–34.7 % and 20.2–35.5 % of the total population suffered from seasonal and perennial water scarcity, respectively, during different periods. Increased water withdrawal and population growth were the primary factors that caused changes in the exposure of the population to water scarcity. Meanwhile, we found that in the absence of upstream water consumption, water scarcity could be alleviated or removed for 4–13.2 % of the downstream population, especially during seasons when water is scarce (e.g., spring and winter). Water efficiency improvements could save 10.1 % of the total water usage (3.3 km3), of which a 7.8 % saving could come from irrigation, roughly 3.4 times the potential saving from industry (2.3 %). Irrigation savings can increase industrial added value by 4 %, while industrial water savings can meet the localized domestic water use of 4 % of urban, or 10 % of rural residents in sub-basins without water scarcity. These findings provide a basis for the design of measures to alleviate water scarcity and facilitate sustainable water resource management in the YRB.

The Effect of Earnings Persistence and Capital Structure on Earnings Response Coefficient in Indonesia Stock Exchange

This study managed to investigate the effect of earnings persistence and leverage on the Earnings Response Coefficient (ERC) in companies listed on the Indonesia Stock Exchange. Based on the annual report data of 265 companies from 2011 to 2021, we show that earnings persistence has a significant and positive impact on ERC, while leverage has a limited impact on ERC. Further findings demonstrate that higher investor sentiment could lead to a larger impact of earnings persistence on ERC. These results imply that, as high earning quality Attracts high investor sentiment in the trading stock, great news can be processed into the price quickly and the price rises in a short period, while bad news could also lead to immediate price corrections with investors’ attention. Thus, we find that a positive relationship between ROE and ERC, and investor sentiment helps strengthen the relationship. Our study adds the studies on price resilience and expands the understanding of the Indonesia Stock Exchange’s features.

Local Excision Versus Radical Resection for Grade 2 Rectal Neuroendocrine Tumors: A Multicenter Propensity Score-Matched Analysis.

Studies on grade 2 rectal neuroendocrine tumors are limited, and the optimal treatment for these tumors is not well established. We aimed to compare the oncologic results of local excision versus radical resection for the treatment of grade 2 rectal neuroendocrine tumors. Retrospective multicenter propensity score-matched study to minimize heterogeneity between groups and focus on the differences between surgery strategies. Seventeen large-scale Chinese medical centers participated in this study. A total of 144 patients with pathologically confirmed grade 2 rectal neuroendocrine tumors were retrospectively analyzed. Cancer-specific survival and relapse-free survival were assessed to compare surgery strategies. A total of 144 patients with grade 2 rectal neuroendocrine tumors were enrolled in this study. Twenty-seven patients underwent endoscopic resection, 55 underwent transanal excision, 50 underwent radical resection, and 12 underwent palliative surgery or biopsy for distant metastasis. Of the 50 patients who underwent radical resection, 30 (60.0%) had clinically positive lymph nodes on the basis of the histopathology results. The optimal cutoff value for tumor size to predict cancer-specific survival was 1.5 cm. In patients with grade 2 rectal neuroendocrine tumors of ≤1.5-cm size, there were no significant differences in cancer-specific survival and relapse-free survival between local excision and radical resection groups ( p > 0.05). In patients with grade 2 rectal neuroendocrine tumors of >1.5-cm size, relapse-free survival was significantly lower in the local excision group than in the radical resection group ( p = 0.04). The nature of retrospective reviews and a relatively short follow-up period are limitations of this study. Grade 2 rectal neuroendocrine tumors have a nonnegligible rate of lymph node metastasis. Local excision is a feasible choice for tumors of ≤1.5 cm size without metastasis, whereas radical resection is more beneficial in those of >1.5 cm size. See Video Abstract . ANTECEDENTES:Los estudios sobre los tumores neuroendocrinos rectales de grado 2 son limitados y el tratamiento óptimo para estos tumores no está bien establecido.OBJETIVO:Comparar los resultados oncológicos de la escisión local versus la resección radical para el tratamiento de tumores neuroendocrinos rectales grado 2.DISEÑO:Estudio multicéntrico retrospectivo emparejado por puntuación de propensión para minimizar la heterogeneidad entre grupos y centrarse en la diferencia entre estrategias quirúrgicas.ESCENARIO:Diecisiete centros médicos chinos de gran tamaño participaron en este estudio.PACIENTES:Se analizaron retrospectivamente un total de 144 pacientes con tumores neuroendocrinos rectales grado 2 patológicamente confirmados.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluaron la supervivencia específica del cáncer y la supervivencia libre de recaída para comparar las estrategias quirúrgicas.RESULTADOS:En este estudio se inscribieron un total de 144 pacientes con tumores neuroendocrinos rectales grado 2. Veintisiete pacientes se sometieron a resección endoscópica, 55 a escisión transanal, 50 a resección radical y 12 a cirugía paliativa o biopsia por metástasis a distancia. De los 50 pacientes que se sometieron a resección radical, 30 (60,0%) tenían ganglios linfáticos clínicamente positivos según los resultados histopatológicos. El valor de corte óptimo para el tamaño del tumor para predecir la supervivencia específica del cáncer fue de 1,5 cm. En pacientes con tumores neuroendocrinos rectales grado 2 ≤ 1,5 cm, no hubo diferencias significativas en la supervivencia específica del cáncer y la supervivencia libre de recaída entre los grupos de escisión local y resección radical ( p >0,05). En pacientes con tumores neuroendocrinos rectales grado 2 > 1,5 cm, la supervivencia libre de recaída fue significativamente menor en el grupo de escisión local que en el grupo de resección radical ( p = 0,04).LIMITACIONES:La naturaleza de la revisión retrospectiva y el período de seguimiento relativamente corto son limitaciones de este estudio.CONCLUSIONES:Los tumores neuroendocrinos rectales grado 2 tienen una tasa no despreciable de metástasis en los ganglios linfáticos. La escisión local es una opción factible para tumores ≤ 1,5 cm sin metástasis, mientras que la resección radical es más beneficiosa en aquellos > 1,5 cm. (Traducción-Dr. Felipe Bellolio ).

Six years of continuous carbon isotope composition measurements of methane in Heidelberg (Germany) – a study of source contributions and comparison to emission inventories

Abstract. Mitigation of greenhouse gases requires a precise knowledge of their sources at both global and regional scales. With improving measurement techniques, in situ δ(13C,CH4) records are analysed in a growing number of studies to characterise methane emissions and to evaluate inventories at regional and local scales. However, most of these studies cover short time periods of a few months, and the results show a large regional variability. In this study, a 6-year time record of in situ δ(13C,CH4), measured with a cavity ring-down spectroscopy (CRDS) analyser in Heidelberg, Germany, is analysed to obtain information about seasonal variations and trends of CH4 emissions. The Keeling plot method is applied to atmospheric measurements on different timescales, and the resulting source contributions are used to evaluate the CH4 emissions reported by two emission inventories: the Emissions Database for Global Atmospheric Research (EDGAR v6.0) and the inventory of the State Institute for the Environment Baden-Württemberg (LUBW). The mean isotopic carbon source signature for the Heidelberg catchment area derived from atmospheric measurements is (-52.3±0.4) ‰ and shows an annual cycle with 5.8 ‰ more depleted values in summer than in winter. This annual cycle can only be partly explained by seasonal variations in the 13C-enriched emissions from heating and reveals strong seasonal variations in biogenic CH4 emissions in the Heidelberg catchment area, which are not included in EDGAR v6.0. The comparison with emission inventories also shows that EDGAR v6.0 overestimates the CH4 emissions from less depleted sources. In situ CH4 isotope analysers at continental and urban monitoring stations can make an important contribution to the verification and improvement of emission inventories.

Environment and Digitalization: The New Paradigms in the European Stock Markets

In a European context in which the objectives of climate neutrality and digitalization appear fundamental, the work analyzes the relationships between the price of the main stock market indices and the most representative variables such as carbon emissions, digitalization, use of renewable energy, research and development expenses, environmental taxes, and all economic and management activities aimed at reducing or eliminating any form of pollution. The analysis was developed through three different regressions involving the long period 1995–2020 and the short period 2017–2020. The results show how increasing carbon emissions and environmental taxes positively impact stock indices. The former is linked to an increase in production and, therefore, economic growth, and the latter encourages sustainability. Taxes on transport and energy in the long term generate higher costs, which damage profitability and negatively impact the performance of stock indices. Finally, in the short term, implementing environmental protection measures or the sustainable management of resources may lead to higher operating costs for the companies involved. These cost increases can negatively impact profit margins and reduce the value of companies. These results, therefore, show us how environmental sustainability has a significant impact on European stock markets; consequently, the relevant regulations and policies should also consider the economic and managerial impacts that companies implement to achieve their objectives of the Green Deal.

Serial reversal learning in nectar-feeding bats

We explored the behavioral flexibility of Commissaris’s long-tongued bats through a spatial serial reversal foraging task. Bats kept in captivity for short periods were trained to obtain nectar rewards from two artificial flowers. At any given time, only one of the flowers provided rewards and these reward contingencies reversed in successive blocks of 50 flower visits. All bats detected and responded to reversals by making most of their visits to the currently active flower. As the bats experienced repeated reversals, their preference re-adjusted faster. Although the flower state reversals were theoretically predictable, we did not detect anticipatory behavior, that is, frequency of visits to the alternative flower did not increase within each block as the programmed reversal approached. The net balance of these changes was a progressive improvement in performance in terms of the total proportion of visits allocated to the active flower. The results are compatible with, but do not depend on, the bats displaying an ability to ‘learn to learn’ and show that the dynamics of allocation of effort between food sources can change flexibly according to circumstances.

One‐pot Three‐component Synthesis of 1,2,4‐Triazolo[4,3‐a] pyrimidines Under the Catalytic Performance of TiO2−Bis[TMS−NH2+ C(NO2)3−] as a Novel Heterogeneous Nano‐catalyst

AbstractIn the current study, N1‐N4‐bis (3‐(trimethoxysilyl) propyl) butane‐1,4‐diammonium trinitromethanide on titanium dioxide {TiO2−Bis [TMS−NH2+ C(NO2)3−]} was synthesized and characterized using a variety of techniques including energy dispersive X‐ray analysis (EDX), fourier transform infrared spectroscopy (FT‐IR), thermo gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), and X‐ray diffraction (XRD). Then TiO2−Bis [TMS−NH2+ C(NO2)3−] was used as an efficient nano‐catalyst in the one‐pot synthesis of 1,2,4‐triazolo[4,3‐a] pyrimidine derivatives at 120 °C under the solvent‐free conditions with good to excellent yields. Easy separation of the products from the catalyst, short period of the reaction times, and reusability of the catalyst are among the most important features of the reported method.

Urbanization Further Intensifies Short‐Duration Rainfall Extremes in a Warmer Climate

AbstractIntensification of short‐duration rainfall extremes contributes to increased urban flood risk. Yet, it remains unclear how upper‐tail rainfall statistics could change with regional warming. Here, we characterize the non‐stationarity of rainfall extremes over durations of 1–24 hr for the rapidly developing coastal megalopolis of the Greater Bay Area, China. Using high‐resolution, multi‐source, merged and gridded data we observe greater increases in rainfall intensities over the north‐central part of the region compared with the southern coastal region. Our results show, for the first time, that urbanization nonlinearly increases rainfall intensities at different durations and return periods. Over short durations (≤3‐hr) and short return periods (2‐yr), urban areas have the greatest scaling rates (≥19.9%/°C). However, over longer durations (≥9‐hr) rural areas have greater scaling rates, with a lower degree of dependency on both durations and return periods.

Catalytic Asymmetric Synthesis of α-Mono and α,α-Disubstituted 5- and 6-Membered α-Aza-lactams

AbstractFive- and six-membered cyclic amide structures with an embedded endocyclic α-aza group (α-aza-lactams) not only represent masked or protected forms of α-amino acids, but also form the core of other medicinally relevant compound families such as (thio)hydantoins and di(tri)ketopiperazines. In recent years, catalytic methods have been discovered to synthesize these molecular scaffolds, particularly those bearing an α-stereogenic tri- or tetrasubstituted carbon center, enantioselectively. The wide variety of methods and catalytic activation strategies that have been successfully applied to this end in a short period of years is notable. This short review covers the most significant, highlighting their differences and complementarities. The methods are organized according to the disconnection approach to the target α-aza-lactam structure, which in most cases is deeply bound to the type of catalysis applied.1 Introduction2 Catalyst-Controlled Cα–H Functionalization (Approach a)3 Decarboxylative α-AAA Reactions (Approach b)4 Cα–X Substitution Reactions (Approach c)5 De Novo Synthesis from Acyclic Precursors (Approach d)6 Hydrogenation of (Addition to) α-Alkyliden-α-aza-lactams (Approach e)7 Kinetic Resolution and Deracemization (Approach f)8 Conclusions

Mental and Physical Symptoms and Perceived Health Risks of Pregnant and Postpartum Women following the Significant Shift in COVID-19 Management in China: A Cross-Sectional Survey

Background. There was a remarkable downgrade in China’s COVID-19 response strategies in January 2023. The COVID-19 infection rate grew rapidly in the early stages following the management policy shift. This study attempted to explore the associations between SARS-CoV-2 infection and mental or physical health status in pregnant and postpartum women and the role of perceived health risks and family members’ SARS-CoV-2 infection status on these associations by capturing the impact of policy shifts in a short period of time. Methods. This cross-sectional study with a random sample from a convenience sample of hospitals was conducted in pregnant and postpartum women in January 2023. Standardized assessment tools were employed to assess anxiety, depressive and physical symptoms, and feelings of hopelessness. Hierarchical multiple logistic regressions were conducted to examine the mechanisms of associations of interests by including a range of sociodemographic factors, self-perceived health, SARS-CoV-2 infection status, and perceived health risks as covariates. Results. Of the 1,013 pregnant and postpartum women aged 32.0 ± 0.3 years, 58.2% (n = 590) were diagnosed with COVID-19, and 49.4% (n = 500) had family members who were infected with SARS-CoV-2. Nearly 98% of the included participants took measures to prevent SARS-CoV-2 infection. A COVID-19 diagnosis was positively associated with feelings of hopelessness (OR = 1.68, 95% CI: 1.20–2.35), probable anxiety (OR = 6.42, 95% CI: 2.18–24.61), possible depression (OR = 2.56, 95% CI: 1.07–6.70), and physical symptoms (OR = 6.28, 95% CI: 1.63–42.03) after adjusting for sociodemographic and health characteristics, while the associations presented no statistical significance when family members’ SARS-CoV-2 infection status and perceived health risks were introduced into the models. Conclusions. Our results suggested that pregnant and postpartum women may experience physical and mental health challenges when they or their family members contracted COVID-19 in the context of a considerable shift in COVID-19 management. Early detection of poor health status and its risk factors for vulnerable groups during shifts in health policy and administrative practice is very necessary, and health services, including easy access to psychosocial support and obstetric counselling, should be prioritized.

Homoeopathy : a Weapon to Children Enemy Ascaris Lumbricoids : a Pilot Study to Study the Effectiveness of Calcarea Carbonica, Cina & Sulphur in Children with Ascariasis

The National Deworming Day is an initiative of Ministry of Health and Family Welfare, Government of India to make every child in the country worm free. This is one of the largest public health programs reaching large number of children during a short period. More than 836 million children are at risk of parasitic worm infections worldwide. According to World Health Organization 241 million children between the ages of 1 and 14 years are at risk of parasitic intestinal worms in India, also known as Soil-Transmitted Helminths (STH). Helminths (worms) which are transmitted through soil contaminated with faecal matter are called soil-transmitted helminths (Intestinal parasitic worms). Roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura) and hookworms (Necator americanus and Ancylostoma duodenale) are worms that infect people.

Study on Temporary Unloading for Chatter Vibration Suppression Using Fixed Superabrasive Polishing Stone with Five-Joint Closed-Link Small Robot and Voice Coil Motor Thrust Control

In this study, an existing superfinishing method used for polishing glass surfaces was refined using a five-joint closed-link compact robot with fixed abrasive grains. In previous studies, a voice coil motor was used to control the constant-pressure pressing force while maintaining the polishing force for a relatively short period. However, maintaining the polishing force for long periods is imperative for achieving a high-quality polished surface. Thus, in this study, a strain gauge load cell was adopted in addition to a conventional piezoelectric force sensor to maintain the polishing force for a long period. First, the amounts of DC drift of the piezoelectric force sensor and strain gauge type load cell were compared to confirm the necessity of signal processing as well as the compatibility of long-term force measurement and high-frequency vibration measurement by application. Further, a method was proposed in which the change in the pressing force was recorded from the connected sensor; when the pressing force fluctuated, chatter vibrations were determined to occur, and the pressing force was temporarily set to 0 N. This method could obtain a better polished surface than the proportional-integral-differential (PID) control, which simply controls the pressing force at a constant value. Finally, chatter vibrations could be determined by detecting high-frequency sounds using a sound level meter. Notably, a finely polished surface could be obtained.

Surface Albedo Feedback, Seasonal Heat Storage and Meridional Heat Transport Determine the Seasonality of Recent Warming in Antarctica

AbstractThe reanalysis data suggest that recent surface warming over Antarctica start in 2016. In this study, using reanalysis data and numerical simulations, I attempt to determine the important mechanisms accounting for seasonal surface warming in Antarctica. The results suggested that seasonal surface warming in Antarctica is mainly determined by the surface energy budget over the Antarctic via horizontal heat advection. The surface energy budget anomaly over the Antarctic, which is mainly determined by anomalous solar radiation absorption, anomalous ocean heat content, and anomalous meridional atmospheric heat transport (AHT), is triggered by Antarctic sea‐ice loss and thus determines the observational seasonality of recent warming in Antarctica via surface horizontal heat advection. In austral summer (December–January–February), additional solar radiation absorption induced by sea‐ice loss and additional AHT from lower latitudes increase the energy budget over the Antarctic. Surface warming, more longwave radiation, and additional energy stored in the upper (deeper) ocean for short (long) time periods explain the additional energy sinks. During austral autumn‐winter (March–August), additional seasonal heat storage (SHS; mainly stored in the upper ocean) is released to the atmosphere and warms the surface. Although the AHT anomaly contributes similarly to the solar radiation absorption/SHS anomaly during April–August, the poleward AHT largely decreased in June due to the weaker eddy activity induced by strong warming at Southern Hemisphere midlatitudes, which counteracts the additional SHS release and cools the Antarctic(a).

Screening for cold tolerance genes in C. elegans, whose expressions are affected by anticancer drugs camptothecin and leptomycin B

Temperature is a vital environmental factor affecting organisms’ survival as they determine the mechanisms to tolerate rapid temperature changes. We demonstrate an experimental system for screening chemicals that affect cold tolerance in Caenorhabditis elegans. The anticancer drugs leptomycin B and camptothecin were among the 4000 chemicals that were screened as those affecting cold tolerance. Genes whose expression was affected by leptomycin B or camptothecin under cold stimuli were investigated by transcriptome analysis. Abnormal cold tolerance was detected in several mutants possessing genes that were rendered defective and whose expression altered after exposure to either leptomycin B or camptothecin. The genetic epistasis analysis revealed that leptomycin B or camptothecin may increase cold tolerance by affecting a pathway upstream of the insulin receptor DAF-2 that regulates cold tolerance in the intestine. Our experimental system combining drug and cold tolerance could be used for a comprehensive screening of genes that control cold tolerance at a low cost and in a short time period.