714 research outputs found
A constructive characterization of total domination vertex critical graphs
AbstractLet G be a graph of order n and maximum degree Δ(G) and let γt(G) denote the minimum cardinality of a total dominating set of a graph G. A graph G with no isolated vertex is the total domination vertex critical if for any vertex v of G that is not adjacent to a vertex of degree one, the total domination number of G−v is less than the total domination number of G. We call these graphs γt-critical. For any γt-critical graph G, it can be shown that n≤Δ(G)(γt(G)−1)+1. In this paper, we prove that: Let G be a connected γt-critical graph of order n (n≥3), then n=Δ(G)(γt(G)−1)+1 if and only if G is regular and, for each v∈V(G), there is an A⊆V(G)−{v} such that N(v)∩A=0̸, the subgraph induced by A is 1-regular, and every vertex in V(G)−A−{v} has exactly one neighbor in A
Parity and Risk of Low Birth Weight Infant in Full Term Pregnancy
Latar belakang: Berat badan lahir rendah meningkatkan morbiditas dan mortalitas pada bayi baru lahir. Hasil Riskesdas 2010 dan 2013 menunjukkan penurunan angka prevalensi berat badan lahir rendah dari 11,1% menjadi 10,2%. Tujuan penelitian ini adalah mengidentifikasi faktor risiko yang berkaitan dengan kejadian berat badan lahir rendah pada kehamilan cukup bulan. Metode: Penelitian potong lintang di dua rumah sakit di Jakarta dengan menggunakan data sekunder. Data rekam medik wanita yang melahirkan pada periode 1 Januari sampai 31 Desember 2011 dipilih secara purposif. Berat badan lahir rendah adalah berat badan kurang dari 2500g pada bayi baru lahir. Analisis data dilakukan dengan menggunakan regresi logistik. Hasil: Pada analisis ini didapatkan 2242 subyek yang memenuhi kriteria, dari 4191 subyek. Proporsi berat badan lahir rendah adalah 9,5%. Jika dibandingkan dengan primipara, wanita nullipara memiliki risiko melahirkan bayi dengan berat badan lahir rendah 46% lebih tinggi [adjusted odds ratio (ORa) = 1.46; P=0.030]. Selanjutnya, jika dibandingkan dengan bayi laki-laki, bayi perempuan memiliki risiko 42% lebih tinggi mengalami berat lahir rendah (ORa = 1.42; P=0.017) Kesimpulan: Bayi berat badan lahir rendah pada kehamilan cukup bulan lebih sering ditemukan pada wanita nullipara dan bayi perempuan. Kata kunci: paritas, jenis kelamin bayi, berat badan lahir rendahBackground: Low birth weight infants tend to increase the occurence of early infant mortality and morbidity. The survey in Indonesia suggested that the prevalence of low birth weight declined from 11.1% in 2010 to 10.2% in 2013. This study aims to identify the risk factors of low birth weight infant in full term pregnancy. Methods: This was a cross-sectional study using secondary data from two hospitals in Jakarta. The data was obtained from medical records of pregnant women who gave birth during the period of January 1 to December 31, 2011. Multivariat logistic regression model with stepwise method was used to analyze the risks of low birth weight. Results: The sample size in this study was 4191 subjects. Out of them 2242 subjects met the inclusion criteria. The proportion of low birth weight was 9.5%. Compared with primipara, nullipara had 46 % increased risk to have LBW infant (ORa = 1.46; P=0.030), meanwhile primipara and nullipara did not have significant difference for having LBW infants (ORa = 0.90; P=0.614). In term of sex of infants, female infant had 42% higher risk of having LBW infant compared with male infant (ORa = 1.42; P=0.017). Conclusion : Low birth weight infants in full term pregnancies are more common in nullipara and most of the LBW infants are femal
Small-Scale Spatial Heterogeneity of Photosynthetic Fluorescence Associated with Biological Soil Crust Succession in the Tengger Desert, China
In dryland regions, biological soil crusts (BSCs) have numerous important ecosystem functions. Crust species and functions are, however, highly spatially heterogeneous and remain poorly understood at a range of scales. In this study, chlorophyll fluorescence imaging was used to quantify millimeter-scale patterns in the distribution and activity of photosynthetic organisms in BSCs of different successional stages (including cyanobacterial, lichen, moss three main successional stages and three intermixed transitional stages) from the Tengger Desert, China. Chlorophyll fluorescence images derived from the Imaging PAM (Pulse Amplitude Modulation) showed that with the succession from cyanobacterial to lichen and to moss crusts, crust photosynthetic efficiency (including the maximum and effective photosynthetic efficiency, respectively) and fluorescence coverage increased significantly (P 0.05) between cyanobacterial and moss crusts, and showed a unimodal pattern of Fv/Fm values. In contrast, photosynthetic heterogeneity was significantly higher in lichen, cyanobacteria-moss and lichen-moss crusts (P < 0.05), with a bimodal pattern of Fv/Fm values. Point pattern analysis showed that the distribution pattern of chlorophyll fluorescence varied at different spatial scales and also among the different crust types. These new results provide a detailed (millimeter-scale) insight into crust photosynthetic mechanisms and spatial distribution patterns associated with their community types. Collectively, this information provides an improved theoretical basis for crust maintenance and management in dryland regions
Numerical simulation on dynamic response of the chest wall loaded by the blast wave
In this paper, a three-dimensional finite element model of the human thorax was constructed using Mimics software and Icem CFD software. This model was loaded with a 100-kPa blast wave and constructed to analyze the dynamic response of the chest wall. The simulation results have shown that a blast wave can cause stress concentration on the ribs and ribs inward movement. The third, fourth, and fifth ribs have the maximum inward moving velocity of 1.6 m / s without any injury for the human body. The three-dimensional finite element model can realistically reflect the characteristic mechanical response of the chest wall to blast wave loadings and can be used for further studies on blast injury mechanism, i.e., injury prediction
Mitochondrial genomes of two Sinochlora species (Orthoptera): novel genome rearrangements and recognition sequence of replication origin
BACKGROUND: Orthoptera, the largest polyneopteran insect order, contains 2 suborders and 235 subfamilies. Orthoptera mitochondrial genomes (mitogenomes) follow the ancestral insect gene order, with the exception of a trnD-trnK rearrangement in Acridomorphs and rare tRNA inversions. A question still remains regarding whether a long thymine-nucleotide stretch (T-stretch) involved in the recognition of the replication origin exists in the control region (CR) of Orthoptera mitochondrial DNA (mtDNA). Herein, we completed the sequencing of whole mitogenomes of two congeners (Sinochlora longifissa and S. retrolateralis), which possess overlapping distribution areas. Additionally, we performed comparative mitogenomic analysis to depict evolutionary trends of Orthoptera mitogenomes. RESULTS: Both Sinochlora mitogenomes possess 37 genes and one CR, a common gene orientation, normal structures of transfer RNA and ribosomal RNA genes, rather low A+T bias, and significant C skew in the majority strand (J-strand), resembling all the other sequenced ensiferans. Both mitogenomes are characterized by (1) a large size resulting from multiple copies of an approximately 175 bp GC-rich tandem repeat within CR; (2) a novel gene order (rrnS-trnI-trnM-nad2-CR-trnQ-trnW), compared to the ancestral order (rrnS-CR-trnI-trnQ-trnM-nad2-trnW); and (3) redundant trnS(UCN) pseudogenes located between trnS(UCN) and nad1. Multiple independent duplication events followed by random and/or non-random loss occurred during Sinochlora mtDNA evolution. The Orthoptera mtDNA recognition sequence of the replication origin may be one of two kinds: a long T-stretch situated in or adjacent to a possible stem-loop structure or a variant of a long T-stretch located within a potential stem-loop structure. CONCLUSIONS: The unique Sinochlora mitogenomes reveal that the mtDNA architecture within Orthoptera is more variable than previously thought, enriching our knowledge on mitogenomic genetic diversities. The novel genome rearrangements shed light on mtDNA evolutionary patterns. The two kinds of recognition sequences of replication origin suggest that the regulatory sequences involved in the replication initiation process of mtDNA have diverged through Orthoptera evolution
Ischemic Stroke in Pontine and Corona Radiata: Location Specific Impairment of Neural Network Investigated With Resting State fMRI
Objective: This study aims to investigate location-specific functional remodeling following ischemic stroke in pons and corona radiata.Methods: This study was approved by the local Institutional Review Board. Written consent was obtained from each of the participants prior to the MRI examination. Thirty six subjects with first ever acute ischemic stroke in pons (PS, n = 15, aged 62.8 ± 11.01 years) or corona radiata (CRS, n = 21, aged 59.33 ± 13.84 years) as well as 30 age and sex matched healthy controls (HC, n = 30, aged 60 ± 6.43 years) were examined with resting state functional magnetic resonance imaging (rs-fMRI). Regional homogeneity (ReHo) and degree centrality (DC) were calculated using a voxel-based approach. Intergroup differences in ReHo and DC were explored using a permutation test with a threshold-free cluster enhancement (PT TFCE, number of permutations = 1,000, family-wise error rate (FWER) < 0.05).Results: ReHo and DC alterations were identified in distributed anatomies for both PS and CRS groups. DC mainly increased in the bilateral anterior and posterior cingulate cortex, the inferior frontal-orbital gyrus, and decreased in the bilateral cuneus, calcarine, and the precuneus, while ReHo mainly decreased in the precentral and the postcentral gyri, inferior parietal lobules, precuneus, posterior cingulate cortex, and the superior occipital gyrus. PS and CRS groups were not significantly different in ReHo or DC (FWER > 0.05).Conclusions: Focal ischemic stroke in pons or corona radiata leads to extensive alterations in the functional network centrality. IS-induced network remodeling is more anatomy-specific than pathway-specific, which may underpin the clinicotopographical profiles during the disease dynamic. Approaches targeting neural pathway and functional connectivity may shed light on a better characterization and management innovation of ischemic stroke
Identification and characterization of the expression profile of microRNAs in Anopheles anthropophagus
BACKGROUND: Anopheles anthropophagus, one of the most important mosquito-borne disease vectors in Asia, mainly takes blood meals from humans and transmits both malaria and filariae. MicroRNAs (miRNAs) are small non-coding RNAs, and play a critical role in many cellular processes, including development, differentiation, apoptosis and innate immunity. METHODS: We investigated the global miRNA expression profile of male and female adults of A. anthropophagus using illumina Hiseq2000 sequencing combined with Northern blot. RESULTS: By using the miRNAs of the closely-related species Anopheles gambiae and Aedes aegypti as reference, we obtained 102 miRNAs candidates out of 12.43 million raw sequencing reads for male and 16.51 million reads for female, with 81 of them found as known miRNAs in An. gambiae and/or Ae. aegypti, and the remaining 21 miRNAs were considered as novel. By analyzing the revised read count of miRNAs in male and female, 29 known miRNAs show sexual difference expression: >2-fold in the read count of the same miRNAs in male and female. Especially for miR-989, which is highly expressed in the female mosquitoes, but shows almost no detected expression in male mosquitoes, indicating that miR-989 may be involved in the physiological activity of female mosquito adults. The expression of four miRNAs in different growth stages of mosquito were further identified by Northern blot. Several miRNAs show the stage-specific expression, of which miR-2943 only expressed in the egg stage, suggesting that miR-2943 may be associated with the development of mosquito eggs. CONCLUSIONS: The present study represents the first global characterization of An. anthropophagus miRNAs in sexual differences and stage-specific functions. A better understanding of the functions of these miRNAs will offer new insights in mosquito biology and has implications for the effective control of mosquito-borne infectious diseases
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