2,048 research outputs found
Parental Origin and Mechanism of Formation of de novo Chromosome Abnormalities : 25 Cases of Numerical and Structural Abnormalities Determined by Restriction Fragment Length Polymorphisms
Parental origin and mechanism of formation of de novo numerical and structural chromosome abnormalities were studied in 25 cases using RFLPs as genetic markers. In 8 of the 10 (5 autosomal and 5 X-chromosomal) numerical abnormalities studied, the origin and the mechanism of formation were ascertained. Of five 21-trisomics, two resulted from a maternal second meiotic nondisjunction, one (a 46/47,+21 mosaic) from mitotic nondisjunction of a paternally-derived chromosome 21, and the remaining two were uninformative. The origin and the mechanism of formation of the additional X chromosomes in the five patients with poly-X chromosomes (a case of XXXXX and four of XXXXY) studied were identical. They all arose through three nondisjunctions at maternal meiosis: once at the first meiosis and simultaneously twice at the second meiosis. These observations indicate that the parental origin of numerical abnormalities is not different between autosomes and X chromosome, the maternal origin being predominant. Of the 15 structural abnormalities studied, the origin was ascertained in 11. An interstitial deletion of chromosome 15 [del(15)(q11.1q12)] in 2 of 5 cases arose at paternal meiosis. A 15q15q translocation in one of 2 cases resulted from centric misdivision of a maternal chromosome 15 followed by duplication of its long-arm, and thus the translocated chromosome is in the condition of maternal uniparental disomy. A case of partial monosomy 21 (monosomy for 21pter-q21.3) resulted from a translocation between paternal chromosomes 2 and 21. The origin of X-chromosomal structural abnormalities in 3 cases were paternal and that in the other 4 cases maternal. Partial X-chromosome duplication [dup(Xp)] in one patient arose through an unequal sister chromatid exchange in the paternal X chromosome, partial deletion [del(Xp)] in one arose at the paternal meiosis, isochromosome X [i(Xq)] in three resulted from centric fission followed by duplication of Xq in a maternal X chromosome, isodicentric chromosome X [inv dup(Xq)] in one arose through an unequal exchange between sister chromatids in a maternal. X chromosome, and ring chromosome X [r(X)] in the other case arose at maternal meiosis. These results on the structural abnormalities suggest that the de novo abnormalities due to events involving centromere disruption arise predominantly during oogenesis, while those due to simple breakage-reunion events occur preferentially during spermatogenesis
Localization and Discrete Beamforming with a Large Reconfigurable Intelligent Surface
In millimeter-wave (mmWave) cellular systems, reconfigurable intelligent
surfaces (RISs) are foreseeably deployed with a large number of reflecting
elements to achieve high beamforming gains. The large-sized RIS will make radio
links fall in the near-field localization regime with spatial non-stationarity
issues. Moreover, the discrete phase restriction on the RIS reflection
coefficient incurs exponential complexity for discrete beamforming. It remains
an open problem to find the optimal RIS reflection coefficient design in
polynomial time. To address these issues, we propose a scalable
partitioned-far-field protocol that considers both the near-filed
non-stationarity and discrete beamforming. The protocol approximates near-field
signal propagation using a partitioned-far-field representation to inherit the
sparsity from the sophisticated far-field and facilitate the near-field
localization scheme. To improve the theoretical localization performance, we
propose a fast passive beamforming (FPB) algorithm that optimally solves the
discrete RIS beamforming problem, reducing the search complexity from
exponential order to linear order. Furthermore, by exploiting the partitioned
structure of RIS, we introduce a two-stage coarse-to-fine localization
algorithm that leverages both the time delay and angle information. Numerical
results demonstrate that centimeter-level localization precision is achieved
under medium and high signal-to-noise ratios (SNR), revealing that RISs can
provide support for low-cost and high-precision localization in future cellular
systems.Comment: 13 page
HeadSculpt: Crafting 3D Head Avatars with Text
Recently, text-guided 3D generative methods have made remarkable advancements
in producing high-quality textures and geometry, capitalizing on the
proliferation of large vision-language and image diffusion models. However,
existing methods still struggle to create high-fidelity 3D head avatars in two
aspects: (1) They rely mostly on a pre-trained text-to-image diffusion model
whilst missing the necessary 3D awareness and head priors. This makes them
prone to inconsistency and geometric distortions in the generated avatars. (2)
They fall short in fine-grained editing. This is primarily due to the inherited
limitations from the pre-trained 2D image diffusion models, which become more
pronounced when it comes to 3D head avatars. In this work, we address these
challenges by introducing a versatile coarse-to-fine pipeline dubbed HeadSculpt
for crafting (i.e., generating and editing) 3D head avatars from textual
prompts. Specifically, we first equip the diffusion model with 3D awareness by
leveraging landmark-based control and a learned textual embedding representing
the back view appearance of heads, enabling 3D-consistent head avatar
generations. We further propose a novel identity-aware editing score
distillation strategy to optimize a textured mesh with a high-resolution
differentiable rendering technique. This enables identity preservation while
following the editing instruction. We showcase HeadSculpt's superior fidelity
and editing capabilities through comprehensive experiments and comparisons with
existing methods.Comment: Webpage: https://brandonhan.uk/HeadSculpt
MiR-455-3p regulates glioma cell proliferation by targeting PAX6
Purpose: To investigate the role of miR-455-3p in gliomas.
Method: Quantitative real-time polymerase chain reaction was used to measure miR-455-3p and paired box 6 (PAX6) levels in glioma cell lines. Western blot analysis was used to determine the expression of cell cycle regulators. In addition to over-expression, silencing of miR-455-3p or PAX6 was performed to study the functions of miR-455-3p in gliomas.
Results: The levels of miR-455-3p were significantly up-regulated in glioma cell lines (p < 0.05), while miR-455-3p over-expression increased glioma cell proliferation and interfered with the progress of the cell cycle (p < 0.01). Furthermore, endogenous miR-455-3p silencing prevented glioma cell proliferation by regulating cell cycle progression (p < 0.05).The results also showed that PAX6 controlled the cell cycle while PAX6 silencing selectively regulated p21 expression (p < 0.01). Furthermore, miR-455-3p and PAX6 influenced p53 expression. Re-introduction of PAX6 expressing vector into glioma cells rescued the pro-tumoral effect of miR-455-3p overexpression.
Conclusion: These findings demonstrate the role of miR-455-3p as a tumour oncogene in gliomas via regulation of the cell cycle, indicating that miR-455-3p might act as a new treatment strategy for glioma cell tumours and a predictor of survival in glioma patients
Joint Optimization of Ranking and Calibration with Contextualized Hybrid Model
Despite the development of ranking optimization techniques, pointwise loss
remains the dominating approach for click-through rate prediction. It can be
attributed to the calibration ability of the pointwise loss since the
prediction can be viewed as the click probability. In practice, a CTR
prediction model is also commonly assessed with the ranking ability. To
optimize the ranking ability, ranking loss (e.g., pairwise or listwise loss)
can be adopted as they usually achieve better rankings than pointwise loss.
Previous studies have experimented with a direct combination of the two losses
to obtain the benefit from both losses and observed an improved performance.
However, previous studies break the meaning of output logit as the
click-through rate, which may lead to sub-optimal solutions. To address this
issue, we propose an approach that can Jointly optimize the Ranking and
Calibration abilities (JRC for short). JRC improves the ranking ability by
contrasting the logit value for the sample with different labels and constrains
the predicted probability to be a function of the logit subtraction. We further
show that JRC consolidates the interpretation of logits, where the logits model
the joint distribution. With such an interpretation, we prove that JRC
approximately optimizes the contextualized hybrid discriminative-generative
objective. Experiments on public and industrial datasets and online A/B testing
show that our approach improves both ranking and calibration abilities. Since
May 2022, JRC has been deployed on the display advertising platform of Alibaba
and has obtained significant performance improvements.Comment: Accepted at KDD 202
Anxiety and depression mediate the relationship between digestive tract conditions and oral health-related quality of life in orthodontic patients
BackgroundAnxiety and depression are common psychological problems in orthodontic patients whose diet habits and oral health status change frequently during treatment. However, relationships between anxiety and depression, digestive tract condition, and impaired oral health-related quality of life remain unknown.Materials and methodsIn this study, clinical assessments, including anxiety, depression, digestive tract condition, and oral health-related quality of life, were collected from 769 outpatients in the orthodontic department using three self-reported questionnaires. Correlation analysis was used to investigate the relationships among different clinical assessments. A chained mediation analysis model was further conducted to explore the direct and indirect effects of these various clinical factors.ResultsChanges in digestive tract conditions were positively correlated with the psychological status and oral health-related quality of life. Anxiety and depression partially mediated the relationship between them, and the indirect effect was 0.68 (30%), of which the mediation effect of anxiety accounted for 56%.ConclusionAnxiety and depression mediate the relationship between gastrointestinal conditions and oral health. In particular, anxiety seems to play a significant mediating role. Our findings indicate that psychological status must be paid more attention to in future clinical practices and supervision for digestive tract symptoms of orthodontic patients
Case report: Localized xanthogranulomatous pyelonephritis in children: A case report and literature review
BackgroundXanthogranulomatous pyelonephritis (XGPN), which is featured by inflammatory destruction of renal parenchyma and fibrosis of kidney, occurs mainly among adults, sporadically among children and rarely among infants. Recurrent urinary tract infections, kidney stone-induced obstructive nephropathy, malnutrition, abnormal lipid metabolism, hypoimmunity, lymphatic obstruction and congenital urinary abnormalities may all cause XGPN among children. Its primary treatment is radical nephrectomy.Case descriptionIn this study, we describe a rare case of XGPN in a 7-year-old boy infected with Staphylococcus aureus (S. aureus). The child presented with symptoms including recurrent fever, urine culture negative. The postoperative pathology confirmed XGPN. Besides, partial nephrectomy was performed.ConclusionXGPN, as a special type of chronic pyelonephritis, is a rare pyelonephritis requiring surgical treatment. Early diagnosis and treatment are crucial to reducing its morbidity and mortality. Although radical nephrectomy is the primary therapeutic option for patients with XGPN, partial nephrectomy surgery should be considered for focal XGPN, aiming to preserve residual renal function in children as far as possible
Molecular dissection of ALS-associated toxicity of SOD1 in transgenic mice using an exon-fusion approach
Mutations in Cu,Zn superoxide dismutase (SOD1) are associated with amyotrophic lateral sclerosis (ALS). Among more than 100 ALS-associated SOD1 mutations, premature termination codon (PTC) mutations exclusively occur in exon 5, the last exon of SOD1. The molecular basis of ALS-associated toxicity of the mutant SOD1 is not fully understood. Here, we show that nonsense-mediated mRNA decay (NMD) underlies clearance of mutant mRNA with a PTC in the non-terminal exons. To further define the crucial ALS-associated SOD1 fragments, we designed and tested an exon-fusion approach using an artificial transgene SOD1T116X that harbors a PTC in exon 4. We found that the SOD1T116X transgene with a fused exon could escape NMD in cellular models. We generated a transgenic mouse model that overexpresses SOD1T116X. This mouse model developed ALS-like phenotype and pathology. Thus, our data have demonstrated that a ‘mini-SOD1’ of only 115 amino acids is sufficient to cause ALS. This is the smallest ALS-causing SOD1 molecule currently defined. This proof of principle result suggests that the exon-fusion approach may have potential not only to further define a shorter ALS-associated SOD1 fragment, thus providing a molecular target for designing rational therapy, but also to dissect toxicities of other proteins encoded by genes of multiple exons through a ‘gain of function’ mechanism
Research on the Food Security Condition and Food Supply Capacity of Egypt
Food security is chronically guaranteed in Egypt because of the food subsidy policy of the country. However, the increasing Egyptian population is straining the food supply. To study changes in Egyptian food security and future food supply capacity, we analysed the historical grain production, yield per unit, grain-cultivated area, and per capita grain possession of Egypt. The GM (1,1) model of the grey system was used to predict the future population. Thereafter, the result was combined with scenario analysis to forecast the grain possession and population carrying capacity of Egypt under different scenarios. Results show that the increasing population and limitations in cultivated land will strain Egyptian food security. Only in high cultivated areas and high grain yield scenarios before 2020, or in high cultivated areas and mid grain yield scenarios before 2015, can food supply be basically satisfied (assurance rate ≥ 80%) under a standard of 400 kg per capita. Population carrying capacity in 2030 is between 51.45 and 89.35 million. Thus, we propose the use of advanced technologies in agriculture and the adjustment of plant structure and cropping systems to improve land utilization efficiency. Furthermore, urbanization and other uses of cultivated land should be strictly controlled to ensure the planting of grains
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