Tipping Point Research Articles

A Randomized, Single-Blind Clinical Trial Comparing Robotic-Assisted Fluoroscopic-Guided with Ultrasound-Guided Renal Access for Percutaneous Nephrolithotomy.

We conducted a randomized, single-blind clinical trial comparing the surgical outcomes of robotic-assisted fluoroscopic-guided (RAF group) and ultrasound-guided (US group) renal access in mini-percutaneous nephrolithotomy (PCNL). We recruited patients who underwent mini-PCNL with ureteroscopic assistance for large renal stones between January 2020 and May 2021. Block randomization was performed using online software. Automated needle target with x-ray was used for fluoroscopic-guided renal access in the RAF group. PCNL was performed by residents using a pneumatic lithotripsy system with 16.5Fr/17.5Fr tracts. The primary outcome was single puncture success, and the secondary outcomes were stone-free rate, complication rate, parameters measured during renal access and fluoroscopy time. In total, 71 patients (35 in US group, 36 in RAF group) were enrolled. No difference was seen in the single puncture success rate between the US and RAF groups (34.3% and 50.0%, p=0.2). In 14.3% cases in the US group vs no cases in the RAF group, the resident was unable to obtain access due to difficult targeting (p=0.025). The mean number of needle punctures was significantly fewer, and the median duration of needle puncture was shorter in the RAF group (1.83 vs 2.51 times, p=0.025; 5.5 vs 8.0 minutes, p=0.049, respectively). The stone-free rate at 3 months after surgery was 83.3% and 70.6% in the RAF and US groups, respectively (p=0.26). Multivariate analysis revealed that RAF guidance reduced the mean number of needle punctures by 0.73 times (p=0.021). RAF renal access in mini-PCNL may have further potential applications in this field.

Emergence of SARS-CoV-2 B.1.1.7 and the Future of Mega Sport Events: Is This the Tipping Point from Pandemic to Endemic?

Emergence of SARS-CoV-2 B.1.1.7 and the Future of Mega Sport Events: Is This the Tipping Point from Pandemic to Endemic?

A cluster randomized controlled trial for measuring the impact of a social norm intervention addressing child marriage in Pirgacha in Rangpur district of Bangladesh: study protocol for evaluation of the Tipping Point Initiative

ABSTRACT Child Marriage (CM) is one of the major developmental concerns in Bangladesh, reporting one of the highest rates of CM (59%) globally. To date, interventions to address CM in Bangladesh have failed to seriously engage with social norms that are important contributors to CM. This paper describes the evaluation design of the Tipping Point Initiative that aims to reduce CM through social norm change and increasing adolescent girls’ agency to voice their rights. The Tipping Point Initiative evaluation trial employs a mixed method design. The quantitative component includes a three-arm Cluster Randomized Controlled Trial design, where Arm 1 receives Tipping Point Program (TPP); Arm 2 receives Tipping Point Program Plus (TPP+), a social norms-enhanced version of TPP; and Arm 3 is the Control. The trial covers 51 clusters (villages) in Pirgacha, in Rangpur district, randomized into three study arms (17 per arms). From each cluster, a cohort of 25 adolescent girls aged 12–<16 years were selected randomly for participation in the survey and intervention. Further, a cross-section of adults (six males and six females) were randomly selected from each cluster for survey. Qualitative baseline data were collected from two purposively selected intervention villages in each intervention arm. Thirty In-Depth Interviews, eight Key Informant Interviews and 16 Focus Group Discussion were conducted with adolescent girls, boys, adult women and men. Same strategies have been followed at endline. The intervention was implemented from April 2019 to December 2020. The endline was conducted 10 months after the end of intervention. Intention-to-treat analysis approach will be used for impact assessment. Both narrative analysis and Grounded Theory approach will be employed in analysing qualitative data. The learnings are expected to inform programs and policies regarding what works and does not work to address CM in such social norms intervention in Bangladesh.

An Analytical Corner Rounding Algorithm With G01 Shape Preserving for Five-Axis Computer Numerical Controlled Machining

Abstract G01 blocks are the widespread format of toolpath in computer numerical controlled (CNC) machining. For achieving smooth motion and eliminating the geometrical discontinuity at the block transitions, various local corner smoothing methods have been developed. However, in these methods, the loss of featured information of parts is inevitable. Focused on this topic, this article proposes a new analytical G2 continuous corner smoothing method with G01 shape preserving for five-axis linear toolpath by locally inserting specially designed B-splines into the corners of consecutive segments. First, by analyzing the condition of G01 shape preserving, the configuration expression of control points for B-splines is yielded for passing through G01 point. On this basis, the tool tip position is smoothed by symmetrical B-splines with minimum curvature in the workpiece coordinate system (WCS). Then, another asymmetrical B-splines is used to smooth tool orientation in the machine coordinate system (MCS). After that, the satisfaction conditions of parametric synchronization between tool tip position and tool orientation are mathematically derived at junctions, while the corresponding maximum smoothing errors are also constrained in WCS. Compared with the existing methods, not only the tool tip points and orientation vectors specified in original G01 blocks are preserved but also the optimal control points considering the curvature of smooth splines can be obtained analytically. Finally, simulations and experiments are performed to validate the effectiveness of the developed method.

Spatial early warning signals for tipping points using dynamic mode decomposition

Tipping points are abrupt transitions in time-varying systems which may be driven by noise, changes in the underlying system, or some combination of the two. Early warning signals of tipping points are potentially valuable leading indicators of these transitions. In low-dimensional systems, it is possible to characterize these indicators based on the expected type of the tipping point. In spatial systems, indicators which take account of changes in the spatial structure are in principle able to capture more information, compared with aggregate measures, and thus provide stronger leading indicators. Here we propose the use of dynamic mode decomposition (DMD), a dimensionality reduction technique first developed in a fluid dynamics context, as a method for extracting useful information about critical slowing down in the leading mode of a spatial system approaching a tipping point. To demonstrate its potential utility for this purpose we employ two models: one drawn from the physiology literature for the study of spatially-patterned ventilation distributions in asthma, and the other an ecological model previously used for the study of spatial early warning signals of tipping points. Together these show that the DMD leading eigenvalue may be a useful spatially-informed early warning signal.

Finding the Tipping Point: When Heterogeneous Evaluations in Social Media Converge and Influence Organizational Legitimacy

Can citizens impact the broader discourse about an organization and its legitimacy? While social media have empowered citizens to publicly question firms through large volumes of online evaluations, the high heterogeneity of their evaluations dilutes their impact. Our empirical study applying a threshold vector autoregressive model (TVAR) analysis of 2.5 million tweets and 1,786 news media articles tests the condition by which the heterogeneity of online evaluations converges and influences the broader media discourse. Although social media evaluations do not initially influence media legitimacy, they become influential after reaching a tipping point of refracted attention, which is created by high volume and convergence of individual evaluations around few aggregative frames. Thus, social media storms may influence the broader discourse about an organization when this discourse converges and reaches a tipping point, rather than merely through the massive participation of citizens.

Transmedia Uprising

Transmedia Uprising

First Report of Tomato Powdery Mildew Caused by Leveillula taurica in Taiwan.

Tomato (Solanum lycopersicum L.) is one of the common and important economic crops in Taiwan. In July 2018, tomato leaves with unusual yellowing and lesions were observed in Taichung, Changhua, Nantou, and Yunlin counties in Taiwan. Symptomatic leaves initially showed chlorotic, irregularly shaped patches on adaxial side of leaves; and days later, necrosis appeared in the patches center. The disease incidence was 4 to 25% and occurred mostly on large type tomato in the field and greenhouse while rarely on cherry tomato. Since the pathogen could not be cultured in potato dextrose agar, for initial pathogen observation, symptomatic leaves were examined directly under light microscope. Conidiophores were found emerged through abaxial stomata of the lesion, and were erect, single and sometimes branched, with single-celled and dimorphic conidia, suggesting the lesions were associated with a powdery mildew. The white to hyaline pathogens collecting directly from fresh signs were also examined. Primary conidia were lanceolate, tip point, 50 to 78 × 14 to 22 μm, ratio of 2.3 to 5.9; secondary conidia were cylindrical to clavate, 47 to 72× 14 to 22 μm, ratio of 2.5 to 4.6. Conidial germ tubes were mainly terminal to subterminal and sometimes lateral. Conidial appressoria were alobate to multilobed, and hyphal appressoria were nipple-shaped, lobed to multilobed or even coralloid. No chasmothecia were found in the field samples. One representative specimens of isolates TARI_PM-3 was deposited in the National Museum of Natural Science in Taiwan (accession number F0034683), and DNA extracted from the fresh conidia was amplified respectively with primers PMITS1 and PMITS2 (Cunnington et al. 2003) for the sequences of internal transcribed spacer region (ITS1+5.8S+ITS2, partial sequence). The segment of sequence (accession numbers MT370494 in GeneBank) showed 99.8% identity with the sequence of AB045000, which was identified as Leveillula taurica (Khodaparast et al., 2001). Based on morphology and molecular analysis, the fungus was identified as L. taurica (Braun and Cook 2012; Choi et al. 2019). To confirm the pathogenicity, conidial suspensions (4 × 104 conidia/ml) of L. taurica (isolate TARI_PM-3) were used to inoculate by dropping (10 μl/site) on the abaxial side of leaves of 4-week-old potted tomato (cv. Golden Lucky). The plants were covered with transparent plastic bags for 1 day and then maintained at 16 to 26°C in a greenhouse. Lesion symptoms of leaves similar to those in the field were observed 4 weeks after inoculation, while the controlled plants inoculated with ddH2O showed symptomless. The same fungus was observed on the necrotic patches of the inoculated leaves. In Taiwan, the recorded causing pathogens of tomato powdery mildew are Erysiphe orontii and E. cichoracearum (Tzen et al. 2019). To our knowledge, this is the first report of tomato powdery mildew caused by L. taurica. Typical lesions appeared in the beginning of the disease progress in the field. Through inoculation, the same pathogen could infect sweet peppers (Capsicum annuum L.), which has been also reported as a host of L. taurica (Tzen et al. 2019), suggesting these two crops could be as alternate hosts of L. taurica in the field. Cross-species infection should be taken into consideration while managing the disease.

Chapter 3 The Tipping Point in Law

Chapter 3 The Tipping Point in Law

Controlled Digital Lending (CDL) at the Tipping Point

Controlled Digital Lending (CDL) at the Tipping Point

Qualitative Endline Results of the Tipping Point Initiative to Prevent Child, Early and Forced Marriage (CEFM) in Nepal

Qualitative Endline Results of the Tipping Point Initiative to Prevent Child, Early and Forced Marriage (CEFM) in Nepal

Theology Past the Climate Tipping Point: What if it is Too Late to Stop Climate Change?

Most of ecotheology is, quite rightly, focused on the strategies that could help stop climate change. This article asks the pessimistic question: what if climate change is already past the point of no return? How should we think about the nature of global change, and what underlying assumptions tend to inform our approaches to climate-change rhetoric and decision making? This provocative article is intended to open up new ecotheological questions about the place of humans in life’s history while asking what hope remains in a world marked by significant climate change.

Tipping Point Leadership Theory to Improve Research Culture in Engineering Education

Indian government is aggressively promoting research culture in universities and institutes across nation. Research and innovation is the most important key for sustainable national growth. This paper presents a case study of tipping point leadership theory to improve research culture in engineering education. Paper presents the steps of problem identification, root cause analysis and process established to improve research culture in CS&amp;IT department. All these points are presented from tipping point leadership perspective. Proposed processes and results are beneficial and roadmap for any higher education department or institute. The analysis shows that the main hurdle to increase research and innovation in higher education institute is cognitive hurdles and motivational hurdles among faculty and students. There is need to promote need and importance of research in academics. Keywords— Cognitive hurdles; Engineering education; Research policy; Tipping point leadership.

Editorial: From Group Identity and the Dark Tetrad to the Tipping Point

Editorial: From Group Identity and the Dark Tetrad to the Tipping Point

Experimental evidence of common pool resource use in the presence of uncertainty

Tipping points can occur in many complex environmental systems and often produce abrupt and irreversible change. Thresholds associated with tipping points are difficult to predict in many cases, leading to considerable challenges associated with the management of natural resources. We use a common pool resource (CPR) framework to investigate the impact of different types of threshold uncertainty on CPR use and the efficacy of coordination among group members. Participants in an economic laboratory experiment made decisions on the use of a CPR under three types of threshold treatments – a known threshold (certainty), an uncertain threshold with a known probability distribution of possible thresholds (risk), and an uncertain threshold with an unknown probability distribution (ambiguity). We also tested the effect of communication on coordination among participants in each treatment. We find that while threshold uncertainty (both risk and ambiguity) tends to increase CPR use, communication reduces the use of shared resources and increases social efficiency. Communication reduces the incidence of coordination failure in the presence of both types of threshold uncertainty. A takeaway from our results is that encouraging communication is likely to improve CPR management, while improving information about the probability of specific thresholds may only be useful if thresholds can be identified with certainty.

An innovative geometric error compensation of the multi-axis CNC machine tools with non-rotary cutters to the accurate worm grinding of spur face gears

As one of the main error sources, the geometric errors are compensated in this work for the accurate worm grinding of spur face gears. The previous methods of the geometric error compensation are usually applied to the machining with rotary cutters, of which the error of cutter rotation angle is not compensated since it does not affect the machining result. These methods are inappropriate to the worm grinding of face gears, because the worm is a non-rotary cutter and the machining result is sensitive to the error of cutter rotation angle. In this work, an innovative geometric error compensation method is proposed to the machining with non-rotary cutters based on two main points. First, the cutter rotation angle is considered to both the modeling and compensation of the geometric errors. Second, the instantaneous ideal contact point, which is calculated according to the generation process of the worm grinding of face gears, is chosen as the reference point to the compensation algorithm rather than the cutter tip point used in the previous method. The proposed method is validated by the example with both the theoretical calculation and practical machining.

Did Recent Marine Heatwaves and Record High Pink Salmon Abundance Lead to a Tipping Point that Caused Record Declines in North Pacific Salmon Abundance and Harvest in 2020?

Did Recent Marine Heatwaves and Record High Pink Salmon Abundance Lead to a Tipping Point that Caused Record Declines in North Pacific Salmon Abundance and Harvest in 2020?

Identifying an Eruption “Tipping Point” in Hot Spot Volcanoes

By analyzing lava samples, researchers show how chemical processes that occur during magma’s ascent to the surface may contribute to a volcano’s eruptible state.

Ultrasonic Imaging Investigation of Tongue Movement Patterns of Cleft-Related Lateralized and Palatalized Misarticulation.

To explore the tongue movement patterns on Mandarin speaking children with repaired cleft palate with lateralized and palatalized misarticulation (LPM) using ultrasound imaging technique. A group of 20 subjects who were diagnosed with speech sound disorder after cleft palate repairment, and another group of 18 children with LPM were recruited. A group of 20 typical children were recruited as the control group. The ultrasonography was used to collect the articulation pattern of the 8 single vowels that are /a/, /o/, / ɘ/, /i/, /u/, /y/, /ɨ/, /ʉ/ in Mandarin Chinese. Various ultrasonic tongue parameters were analyzed from both sagittal and coronal planes. Compared with the control group, coronal height of peak point, coronal tongue dorsum constraint index, sagittal peak point offset distance, sagittal distance between tongue tip and peak point, and sagittal tongue dorsum constraint index of /ɘ/,/i/, /y/ and /ɨ/ were significantly smaller in the cleft-related lateralized and palatalized group (CLP) and noncleft-related lateralized and palatalized group (NLP) ( P < 0.05). Compared with the noncleft-related later- alized and palatalized group and control group, sagittal peak point offset distance of the vowels /ɘ/ and /i/ was significant smaller in the cleft-related lateralized and palatalized group group ( P < 0.05). The ultrasound images on the children with cleft palate showed a midline elevation of the tongue and a significant apical constriction. The children with LPM showed a midline elevation at the coronal plane and anterior movement of the tongue high point at the sagittal plane. The apical vowels were more informative and accurate in indicating the features of LPM than other vowels.

Automatic detection of abrupt transitions in paleoclimate records.

Bifurcations and tipping points (TPs) are an important part of the Earth system's behavior. These critical points represent thresholds at which small changes in the system's parameters or in the forcing abruptly switch it from one state or type of behavior to another. Current concern with TPs is largely due to the potential of slow anthropogenic forcing to bring about abrupt, and possibly irreversible, change to the physical climate system and impacted ecosystems. Paleoclimate proxy records have been shown to contain abrupt transitions, or "jumps," which may represent former instances of such dramatic climate change events. These transitions can provide valuable information for identifying critical TPs in current and future climate evolution. Here, we present a robust methodology for detecting abrupt transitions in proxy records that is applied to ice core and speleothem records of the last climate cycle. This methodology is based on the nonparametric Kolmogorov-Smirnov (KS) test for the equality, or not, of the probability distributions associated with two samples drawn from a time series, before and after any potential jump. To improve the detection of abrupt transitions in proxy records, the KS test is augmented by several other criteria and it is compared with recurrence analysis. The augmented KS test results show substantial skill when compared with more subjective criteria for jump detection. This test can also usefully complement recurrence analysis and improve upon certain aspects of its results.