Developing an integrated genomic selection approach beyond biomass for varietal protection and nutritive traits in perennial ryegrass (Lolium perenne L.).

KEY MESSAGE: Breeding target traits can be broadened to include nutritive value and plant breeder's rights traits in perennial ryegrass by using in-field regression-based spectroscopy phenotyping and genomic selection. Perennial ryegrass breeding has focused on biomass yield, but expansion into a broader set of traits is needed to benefit livestock industries whilst also providing support for intellectual property protection of cultivars. Numerous breeding objectives can be targeted simultaneously with the development of sensor-based phenomics and genomic selection (GS). Of particular interest are nutritive value (NV), which has been difficult and expensive to measure using traditional phenotyping methods, resulting in limited genetic improvement to date, and traits required to obtain varietal protection, known as plant breeder's rights (PBR) traits. In order to assess phenotyping requirements for NV improvement and potential for genetic improvement, in-field reflectance-based spectroscopy was assessed and GS evaluated in a single population for three key NV traits, captured across four timepoints. Using three prediction approaches, the possibility of targeting PBR traits using GS was evaluated for five traits recorded across three years of a breeding program. Prediction accuracy was generally low to moderate for NV traits and moderate to high for PBR traits, with heritability highly correlated with GS accuracy. NV did not show significant or consistent correlation between timepoints highlighting the need to incorporate seasonal NV into selection indexes and the value of being able to regularly monitor NV across seasons. This study has demonstrated the ability to implement GS for both NV and PBR traits in perennial ryegrass, facilitating the expansion of ryegrass breeding targets to agronomically relevant traits while ensuring necessary varietal protection is achieved.

Direct measurement of Ni incorporation into Fe3O4(001).

The normal incidence X-ray standing wave (NIXSW) technique has been used to follow the evolution of the adsorption geometry of Ni adatoms on the Fe3O4(001)-(√2 × âˆš2)R45° surface as a function of temperature. Two primary surface region sites are identified: a bulk-continuation tetrahedral site and a sub-surface octahedral site, the latter site being preferred at higher annealing temperatures. The ease of incorporation is linked to the presence of subsurface cation vacancies in the (√2 × âˆš2)R45° reconstruction and is consistent with the preference for octahedral coordination observed in the spinel compound NiFe2O4.

Efficacy and tolerability of treatment with single doses of diethylcarbamazine (DEC) and DEC plus albendazole (ABZ) for three consecutive years in lymphatic filariasis: a field study in India.

Lymphatic filariasis (LF) affects 73 countries, causes morbidity and impedes socioeconomic development. We had found no difference in safety and micro (Mf) and macro filarial action of single-dose diethylcarbamazine (DEC) and DEC + albendazole (ABZ) in an F01 study done in India (year 2000). There was a programmatic need to evaluate safety and efficacy of multiple annual treatments (F02). Subjects (155) from the F01 study, meeting inclusion-exclusion criteria, were enrolled in F02 and treated with further two annual doses of DEC or DEC + ABZ. Efficacy was evaluated for Mf positivity by peripheral smear (PS) and nucleopore (NP) filter, circulating filarial antigen (CFA) and filarial dance sign (FDS) positivity and Mf count at yearly follow-up. Safety was assessed for 5 days after drug administration. Total of 139 subjects evaluated for efficacy (69 DEC and 70 DEC + ABZ group). Mf positivity prevalence declined progressively by 95% (PS), 66% (NP), and 95% (PS) and 86% (NP); CFA positivity prevalence declined by 15% and 9%; FDS by 100% each; Mf count declined by 75.5 and 76.9% with three annual treatment of DEC and DEC + ABZ, respectively. Addition of ABZ did not show any advantage over DEC given as three annual rounds for LF. DEC and DEC + ABZ were well tolerated. There was no correlation between result of CFA and FDS, (both claimed to be indicative of adult worm). Analysis of published studies and our data indicate that macrofilaricidal effect of DEC/DEC + ABZ may be seen in children and not adults, with three or more annual dosing.

Radiation release at the nation's only operating deep geological repository--an independent monitoring perspective.

Recent incidents at the nation's only operating deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP), resulted in the release of americium and plutonium from one or more defense-related transuranic (TRU) waste containers into the environment. WIPP is a U.S. Department of Energy mined geologic repository that has been in operation since March, 1999. Over 85,000 m3 of waste in various vented payload containers have been emplaced in the repository. The primary radionuclides within the disposed waste are 239+240Pu and 241Am, which account for more than 99% of the total TRU radioactivity disposed and scheduled for disposal in the repository. For the first time in its 15 years of operation, there was an airborne radiation release from the WIPP at approximately 11:30 PM Mountain Standard Time (MST) on Friday, February 14, 2014. The radiation release was likely caused by a chemical reaction inside a TRU waste drum that contained nitrate salts and organic sorbent materials. In a recent news release, DOE announced that photos taken of the waste underground showed evidence of heat and gas pressure resulting in a deformed lid, in material expelled through that deformation, and in melted plastic and rubber and polyethylene in the vicinity of that drum. Recent entries into underground Panel 7 have confirmed that at least one waste drum containing a nitrate salt bearing waste stream from Los Alamos National Laboratory was breached underground and was the most likely source of the release. Further investigation is underway to determine if other containers contributed to the release. Air monitoring across the WIPP site intensified following the first reports of radiation detection underground to ascertain whether or not there were releases to the ground surface. Independent analytical results of air filters from sampling stations on and near the WIPP facility have been released by us at the Carlsbad Environmental Monitoring & Research Center and confirmed trace amounts of 241Am and 239+240Pu, at ratios reflecting the suspect waste stream. The highest activity detected offsite was 115.2 µBq/m3 for 241Am and 10.2 µBq/m3 for 239+240 Pu. These concentrations in air were very small, localized, and below any level of public health or environmental concern.

Demonstration of CW mode locked Cr:forsterite laser using self-shortening and transverse mode degeneracy driven mode locking.

This paper reports a nearly Fourier transform limited CW mode locked Cr:forsterite laser at 1282 nm, with 131 fs pulse duration, based on self-shortening and transverse mode degeneracy (TMD) driven mode locking, operating near the point of fourth-order TMD. The cavity employs a combination of instantaneous intensity driven self-shortening, and operation on the right side of the fourth-order TMD, to generate the self-amplitude modulation necessary for self-mode locking.

Season-dependent effect of thermopulse on gonadal recrudescence in the female catfish, Clarias batrachus.

In the present study, the female Clarias batrachus, held under long photoperiod (13L:11D), were exposed to high water temperature either constantly (24 h) and/or in form of thermopulse of 6 h and 12 h durations, separately, at different times of the day/night cycle for six weeks during the early post-spawning and late post-spawning phases of its reproductive cycle. The effects of high water temperature (30 +/- 1 degrees C) on gonadosomatic index (GSI), plasma levels of testosterone (T) and oestradiol-17beta (E2) were observed. During the late post-spawning phase, thermopulse of 12 h duration given in the morning hour increased all the studied parameters most effectively as compared to that given at evening hour of the day/night cycle or even in comparison to the fish exposed to constant high temperature. Thermopulse of 6 h duration given in the morning or noon also raised these parameters compared to the controls, but the magnitudes of stimulation were moderate. However, exposures of the catfish to such photothermal regimes during the early post-spawning phase completely failed to bring any change in the studied parameters. These findings, thus, clearly indicate that treatment with high temperature under long photoperiod may stimulate gonadal activity in C. batrachus, provided given at appropriate season of the year. A diurnal basis of response to high temperature and the existence of a rigid gonado-refractory phase (perhaps just after the spawning) are also evident in the reproductive cycle of C. batrachus.

The immediate impact of mandatory helmet law on maxillo-facial trauma: A comparative study in a major trauma center, Uttar Pradesh.

Aim: To analyze the effect of the mandatory helmet rule in helmet usage among motorcycle riders and on facial trauma and to determine the significance of difference in the possibility of facial trauma between the helmeted and non-helmeted motorcycle riders. Setting and Design: A retrospective comparative study conducted in a major trauma center at Uttar Pradesh. Material and Method: Data for the present study was obtained from records of the Emergency Department of Trauma Center, for a period of two months before and after the implementation of The Motor Vehicles Act in UP. The study included patients with a history of non-fatal motorcycle accidents who sustained facial injuries regardless of the presence of injuries to other areas of the body during the study period. Information regarding helmet usage during the accident was also recorded. The results were compared between the pre-law period and post-law period. Statistical Analysis Used: Sample t-test was applied to find the level of significance. Results: Out of 219 injured patients, 152 (69.40%) subjects were not wearing helmets, whereas only 67 (30.59%) subjects were wearing helmets. It was observed that around 68.18% of people stated wearing helmets after law implementation with a statistical significance (P value < 0.05). Conclusion: Our study shows that the mandatory helmet rule with elevated penalty rates has significantly increased the usage of helmet among the motorcycle riders, and it also proves that the possibility of facial trauma is significantly higher in non-helmeted riders when compared to helmeted riders.

Adatoms and clusters of 3d transition metals on graphene: electronic and magnetic configurations.

We investigate the electronic and magnetic properties of single Fe, Co, and Ni atoms and clusters on monolayer graphene (MLG) on SiC(0001) by means of scanning tunneling microscopy (STM), x-ray absorption spectroscopy, x-ray magnetic circular dichroism (XMCD), and ab initio calculations. STM reveals different adsorption sites for Ni and Co adatoms. XMCD proves Fe and Co adatoms to be paramagnetic and to exhibit an out-of-plane easy axis in agreement with theory. In contrast, we experimentally find a nonmagnetic ground state for Ni monomers while an increasing cluster size leads to sizeable magnetic moments. These observations are well reproduced by our calculations and reveal the importance of hybridization effects and intra-atomic charge transfer for the properties of adatoms and clusters on MLG.

First Report of Apple Top Working Disease Caused by Viruses (Apple stem grooving virus, Apple chlorotic leaf spot virus, and Apple stem pitting virus) in Apple in India.

Top working of apple (Malus domestica Borkh.) trees of old, unproductive, and less preferred cultivars with the newly introduced spur type commercial cultivars has become a common practice with many growers in the northwestern Himalayan region of India. Typical viral symptoms of curling, puckering, and necrosis on leaves were observed with an incidence of 80% on Red Chief, Super Chief, Scarlet Spur, Schillet Spur, Washington Red Delicious, and many other newly introduced cultivars during surveys conducted in May and June 2009. Leaf samples from top worked trees were tested for the presence of Apple stem grooving virus (ASGV), Apple chlorotic leaf spot virus (ACLSV), and Apple stem pitting virus (ASPV) by employing biological detection (herbaceous and woody indicators), double antibody sandwich (DAS)-ELISA), and reverse transcriptase (RT)-PCR based detection. Mechanical transmission to herbaceous indicators produced chlorotic lesions on Chenopodium quinoa and C. amaranticolor, whereas marginal necrosis was induced on Phaseolous vulgaris within 9 to 21 days after sap inoculations. All three viruses, i.e., ASGV, ASPV, and ACLSV, were detected from these herbaceous indicators in DAS-ELISA (BIOREBA AG, Switzerland). Furthermore, symptoms similar to those observed in orchards were produced when the test budwood was inoculated onto the woody indicator (M. pumila 'Spy 227') plant by double grafting, grafting cum budding, and double budding methods within time periods ranging from 4 months in double grafting, 5 months in double budding, to 1 year 4 months in the grafting cum budding method. The presence of all three viruses was confirmed by DAS-ELISA again in Spy 227 woody indicator. PCR detection was carried out by using the coat protein gene specific primers (ASGV5641 [forward], ASGV6396 [reverse]; ACLSV6784 [forward], ACLSV7365 [reverse] [2]; ASP-C [sense], ASP-A [anti-sense] [1]) of all the viruses detected through ELISA. The amplified products were cloned, sequenced, and deposited in NCBI (GenBank Accessions KC110892 for ASGV, KC154859 for ASPV, and KC154862 for ACLSV). BLASTn analysis showed the ASGV isolate had 97 to 98% sequence identity with Indian (FM204881) and Brazilian (AF438409) ASGV isolates. The ASPV and ACLSV isolates had 98% and 99% sequence identity with Chinese (JF895517) and Japanese (AB326230) isolates, respectively. To the best of our knowledge, this is the first report of apple top working disease associated with ASGV, ASPV, and ACLSV infection in commercial cultivars of apple from India and seems to be a serious threat for growing virus-free healthy stocks in orchards. Top working disease in apple associated with ASGV, ASPV, and ACLSV viruses has been reported from Japan (3,4). References: (1) J. K. Kundu et al. Plant Prot. Sci. 39:88, 2003. (2) O. Nickel et al. Fitopatol. Brasil. 26:655, 2001. (3) H. Yanase. Bull. Fruit Tree Res. Stn., Japan Ser. C 1:47, 1974. (4) H. Yanase et al. Acta Hortic. 44:221, 1975.

Plutonium in the WIPP environment: its detection, distribution and behavior.

The Waste Isolation Pilot Plant (WIPP) is the only operating deep underground geologic nuclear repository in the United States. It is located in southeastern New Mexico, approximately 655 m (2150 ft) below the surface of the Earth in a bedded Permian evaporite salt formation. This mined geologic repository is designed for the safe disposal of transuranic (TRU) wastes generated from the US defense program. Aerosol and soil samples have been collected near the WIPP site to investigate the sources of plutonium in the WIPP environment since the late 1990s, well before WIPP received its first shipment. Activities of (238)Pu, (239+240)Pu and (241)Am were determined by alpha spectrometry following a series of chemical separations. The concentrations of Al and U were determined in a separate set of samples by inductively coupled plasma mass spectrometry. The annual airborne concentrations of (239+240)Pu during the period from 1998 to 2010 show no systematic interannual variations. However, monthly (239+240)Pu particulate concentrations show a typical seasonal variation with a maximum in spring, the time when strong and gusty winds frequently give rise to blowing dust. Resuspension of soil particles containing weapons fallout is considered to be the predominant source of plutonium in the WIPP area. Further, this work characterizes the source, temporal variation and its distribution with depth in a soil profile to evaluate the importance of transport mechanisms affecting the fate of these radionuclides in the WIPP environment. The mean (137)Cs/(239+240)Pu, (241)Am/(239+240)Pu activity ratio and (240)Pu/(239)Pu atom ratio observed in the WIPP samples are consistent with the source being largely global fallout. There is no evidence of any release from the WIPP contributing to radionuclide concentrations in the environment.

Radioactive fallout in the United States due to the Fukushima nuclear plant accident.

The release of radioactivity into the atmosphere from the damaged Fukushima Daiichi nuclear power plant started on March 12th, 2011. Among the various radionuclides released, iodine -131 ((131)I) and cesium isotopes ((137)Cs and (134)Cs) were transported across the Pacific Ocean and reached the United States on 17-18 March 2011. Consequently, an elevated level of fission products (131)I, (132)I, (132)Te, (134)Cs and (137)Cs were detected in air, water, and milk samples collected across the United States between March 17 and April 4, 2011. The continuous monitoring of activities over a period of 25 days and spatial variations across more than 100 sampling locations in the United States made it possible to characterize the contaminated air masses. For the entire period, the highest detected activity values ranged from less than 1 m Bq m(-3) to 31 m Bq m(-3) for the particulate (131)I, and up to 96 m Bq m(-3) for the gaseous (131)I fraction.

Prevalence of Non-alcoholic Fatty Liver Disease in India: A Systematic Review and Meta-analysis.

Background: Non-alcoholic fatty liver disease (NAFLD) contributes to a large proportion of liver disease burden in the world. Several groups have studied the prevalence of NAFLD in the Indian population. Aim: A systematic review of the published literature and meta-analysis was carried out to estimate the prevalence of NAFLD in the Indian population. Methods: English language literature published until April 2021 was searched from electronic databases. Original data published in any form which had reported NAFLD prevalence in the Indian population were included. The subgroup analysis of prevalence was done based on the age (adults or children) and risk category, i.e., average-risk group (community population, participants of control arm, unselected participants, hypothyroidic individuals, athletes, aviation crew, and army personnel) and high-risk group (obesity or overweight, diabetes mellitus, coronary artery disease, etc.). The prevalence estimates were pooled using the random-effects model. Heterogeneity was assessed with I2. Results: Sixty-two datasets (children 8 and adults 54) from 50 studies were included. The pooled prevalence of NAFLD was estimated from 2903 children and 23,581 adult participants. Among adults, the estimated pooled prevalence was 38.6% (95% CI 32-45.5). The NAFLD prevalence in average-risk and high-risk subgroups was estimated to be 28.1% (95% CI 20.8-36) and 52.8% (95% CI 46.5-59.1), respectively. The estimated NAFLD prevalence was higher in hospital-based data (40.8% [95% CI 32.6-49.3%]) than community-based data (28.2% [95% CI 16.9-41%]). Among children, the estimated pooled prevalence was 35.4% (95% CI 18.2-54.7). The prevalence among non-obese and obese children was 12.4 (95% CI 4.4-23.5) and 63.4 (95% CI 59.4-67.3), respectively. Conclusion: Available data suggest that approximately one in three adults or children have NAFLD in India.

Coupling single molecule magnets to ferromagnetic substrates.

We investigate the interaction of TbPc(2) single molecule magnets (SMMs) with ferromagnetic Ni substrates. Using element-resolved x-ray magnetic circular dichroism, we show that TbPc(2) couples antiferromagnetically to Ni films through ligand-mediated superexchange. This coupling is strongly anisotropic and can be manipulated by doping the interface with electron acceptor or donor atoms. We observe that the relative orientation of the substrate and molecule anisotropy axes critically affects the SMM magnetic behavior. TbPc(2) complexes deposited on perpendicularly magnetized Ni films exhibit enhanced magnetic remanence compared to SMMs in the bulk. Contrary to paramagnetic molecules pinned to a ferromagnetic support layer, we find that TbPc(2) can be magnetized parallel or antiparallel to the substrate, opening the possibility to exploit SMMs in spin valve devices.

Electronic and magnetic reconstructions in La0.7Sr0.3MnO3/SrTiO3 heterostructures: a case of enhanced interlayer coupling controlled by the interface.

We report on the magnetic coupling of La0.7Sr0.3MnO3 layers through SrTiO3 spacers in La0.7Sr0.3MnO3/SrTiO3 epitaxial heterostructures. Combined aberration-corrected microscopy and electron-energy-loss spectroscopy evidence charge transfer to the empty conduction band of the titanate. Ti d electrons interact via superexchange with Mn, giving rise to a Ti magnetic moment as demonstrated by x-ray magnetic circular dichroism. This induced magnetic moment in the SrTiO3 controls the bulk magnetic and transport properties of the superlattices when the titanate layer thickness is below 1 nm.

Phosphorylation of Snapin by PKA modulates its interaction with the SNARE complex.

cAMP-dependent protein kinase A (PKA) can modulate synaptic transmission by acting directly on unknown targets in the neurotransmitter secretory machinery. Here we identify Snapin, a protein of relative molecular mass 15,000 that is implicated in neurotransmission by binding to SNAP-25, as a possible target. Deletion mutation and site-directed mutagenetic experiments pinpoint the phosphorylation site to serine 50. PKA-phosphorylation of Snapin significantly increases its binding to synaptosomal-associated protein-25 (SNAP-25). Mutation of Snapin serine 50 to aspartic acid (S50D) mimics this effect of PKA phosphorylation and enhances the association of synaptotagmin with the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex. Furthermore, treatment of rat hippocampal slices with nonhydrolysable cAMP analogue induces in vivo phosphorylation of Snapin and enhances the interaction of both Snapin and synaptotagmin with the SNARE complex. In adrenal chromaffin cells, overexpression of the Snapin S50D mutant leads to an increase in the number of release-competent vesicles. Our results indicate that Snapin may be a PKA target for modulating transmitter release through the cAMP-dependent signal-transduction pathway.

Electronic structure studies of nanoferrite Cu(x)Co(1-x)Fe2O4 by X-ray absorption spectroscopy.

Pure and mixed cobalt copper ferrites are of great interest due to their widespread application in electronics and medicine. We report on the electronic structure of a nanoferrite Cu(x)Co(1-x)Fe2O4 (0.0 < or = x < or = 1.0) system studied by X-ray absorption spectroscopy. These magnetic nanoferrites (average crystallite size approximately 31-43 nm) were synthesized by an auto combustion method and are characterized by high resolution X-ray diffraction and near edge X-ray absorption fine structure measurements at the O K and Co, Cu, and Fe L-edges. The O K-edge spectra suggest that there is a strong hybridization between O 2p and 3d electrons of Co, Cu and Fe cations and Fe L3,2-edge spectra indicate that Fe ions coexist in mixed valence states (Fe3+ and Fe2+) at tetrahedral and octahedral sites of the spinel structure. Copper and cobalt ions are distributed in the divalent state in octahedral sites of the spinel structure. The origin of high saturation magnetization and coercivity in cobalt-copper ferrites are explained in light of these results.

Changing Trends In Electrical Burns From A Tertiary Care Centre - Epidemiology And Outcome Analysis.

Electrical burn injuries result in significant mortality and morbidity. Most of these injuries are preventable. We conducted a retrospective analysis of various aspects of electrical injuries presenting to our center over a period of 1 year from September 2018 to August 2019. Demographic characteristics of patients along with burn characteristics and associated injuries were analysed. Outcomes including length of hospital stay, need for fasciotomy, amputation, renal failure and mortality were also analysed. A total of 6380 patients presented to our center during the study period, of which 471 (7.38%) had electrical burns. Total burn admissions were 1530, of which 283 (18.49%) patients were admitted with electrical burns. The mean age in our cohort was 25.31±12.76 years and mean TBSA was 29.22±23.81%. The most common cause of electrical burns was occupational (33.3%), followed by those that occurred on the rooftop of houses (31%). A historical comparison with data published from our center in 2011 showed a significant increase in occupational burns (18.72% vs. 33.3%) and rooftop electrical burns (8.21% vs. 31%), and a decrease in agriculture-related (42.46% vs. 9.1%) and domestic electrical burns (26.02% vs. 6.7%). There was also a significant rise in proportion of high voltage injuries (71.23% vs. 86.90%). Logistic regression analysis showed electric contact burn to be a risk factor for fasciotomy and limb gangrene. Risk factors for renal failure were age, percentage burn, electric contact burn and rural residence, and those for mortality were percentage burn and renal failure. Emphasis on preventive strategies, especially against occupational injuries and injuries occurring on rooftops, is necessary to prevent such devastating injuries.

Les brûlures électriques sont responsables d'une morbidité et d'une mortalité significatives, quand la plupart d'entre elles peuvent être prévenues. Nous avons étudié rétrospectivement les brûlures électriques vues dans notre service entre septembre 2018 et août 2019 inclus (données démographiques, caractéristiques de la brûlure, lésions associées, durée d'hospitalisation, aponévrotomies, amputations, défaillances rénales, mortalité). Quatre cent soixante et onze des 6 380 (7,38%) patients s'étant présentés souffraient de brûlures électriques. Deux cent quatre- vingt- trois des 1 530 (18,49%) hospitalisés l'étaient en raison de brûlures électriques. L'âge moyen était de 25,31 +/- 12,76 ans, la surface brûlée de 29,22 +/- 23,81%. La brûlure survenait au travail dans 1/3 des cas, au domicile (sur le toit) dans 31% des cas. Comparativement aux données historiques de notre CTB (datant de 2011), on constate une recrudescence des accidents de travail (qui passent de 18,72 à 33,3%) et de ceux survenant sur le toit du domicile (de 8,21 à 31%) alors que ceux chez les agriculteurs (de 42,46% à 9,1%) et les accidents domestiques (de 26,02 à 6,7%) baissent. La proportion des accidents à haut voltage a augmenté de 71,23 à 86,9%. En régression logistique, la brûlure électrothermique est un facteur de risque d'aponévrotomie et de gangrène de membre. Les facteurs de risque d'insuffisance rénale étaient l'âge, la surface brûlée, la brûlure électrothermique et la ruralité. Les facteurs de risque de mortalité étaient la surface brûlée et la défaillance rénale. Les mesures préventives doivent se focaliser sur les accidents de travail et le risque encouru sur les toits des habitations.

Variables to predict spontaneous eruption of palatally displaced permanent canine after interceptive extraction of primary canine: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the effectiveness of different diagnostic variables measured on panoramic radiographs (PAN) to predict spontaneous eruption of palatally displaced canine (PDC) after interceptive extraction in late mixed dentition. MATERIALS AND METHODS: Digital databases (MEDLINE, CENTRAL (Cochrane), Scopus, clinicaltrials.gov, ISRCTN registry) and hand searches were performed up to March 2020. Both randomized and non-randomized controlled trials were considered for the review. Study selection, data extraction, risk of bias assessment (RoB2.0 and ROBINS-I), and the certainty of evidence evaluation (GRADE) were performed according to Cochrane Handbook for Systematic Reviews of Interventions. The random-effects method for quantitative synthesis of dichotomous as well as continuous data was used. RESULTS: Out of 767 retrieved records, 4 controlled trials fulfilled the eligibility criteria and were included in the review. Studies were assessed at low risk of bias except one. Overall certainty was strong to moderate. PDCs in distal sectors (RR: 1.621; 95%CI: 1.259 to 2.086; P<0.001) and alpha-angle <30° (SMD: -1.350; 95%CI: 1.924 to -0.776; P<0.001) were significantly benefited from interceptive extraction. However, Vertical distance of PDC cusp tip from occlusal plane had statistically insignificant (p: 0.855) roll on eruption prediction. CONCLUSION: Interceptive extraction at a younger age, initial horizontal localization (sector position), and alpha-angle (initial mesial inclination) are the most important variables predicting the spontaneous eruption of palatally displaced canines. Findings of this review can be utilized to make evidence-based decisions for managing PDCs with diverse sectors and mesial inclinations. However, well-designed clinical trials are recommended to strengthen the evidence.