Study on the effects of stand density management of Chinese fir plantation in Northern China.

The aim of this study was to clarify the mechanism by which thinning alters stand structure and affects forest productivity by characterizing changes in stand quantitative maturity age, stand diameter distribution, structural heterogeneity, and forest productivity of Chinese fir plantations at different thinning times and intensities. Our findings provide insights into how the density of stands could be modified to enhance the yield and timber quality of Chinese fir plantations. The significance of differences in individual tree volume, stand volume, and timber merchantable volume was determined using one-way analysis of variance and post hoc Duncan tests. The stand quantitative maturity age was obtained using the Richards equation. The quantitative relationship between stand structure and productivity was determined using a generalized linear mixed model. We found that (1) the quantitative maturity age of Chinese fir plantations increased with thinning intensity, and the quantitative maturity age was much greater under commercial thinning than under pre-commercial thinning. (2) Individual tree volume and the proportion of medium-sized and large-sized timber merchantable volume increased with stand thinning intensity. Thinning promoted increases in stand diameter. pre-commercially thinned stands were dominated by medium-diameter trees when the quantitative maturity age was reached, whereas commercially thinned stands were dominated by large-diameter trees. The living trees volume will decrease immediately after thinning, and then it will gradually increase with the age of the stand. When the stand volume included both living trees volume and thinned volume, thinned stands increased stand volume compared with unthinned stands. In pre-commercial thinning stands, the greater the intensity of thinning, the greater the increase in stand volume, and the opposite was true for commercial thinning. (3) Thinning also reduced heterogeneity in stand structure, which was lower after commercial thinning than after pre-commercial thinning. The productivity of pre-commercially thinned stands increased with thinning intensity, whereas that of commercially thinned stands decreased with thinning intensity. (4) The structural heterogeneity of pre-commercially and commercially thinned stands was negatively and positively correlated with forest productivity, respectively. In the Chinese fir plantations in the hilly terrain of the northern Chinese fir production area, when pre-commercial thinning was performed in the ninth year to a residual density of 1750 trees per hectare, the stand quantitative maturity age was reached in year 30, medium-sized timber accounted for 75.2% of all trees, and the stand volume was 667.9 m3 per hectare. This thinning strategy is favorable for producing medium-sized Chinese fir timber. When commercial thinning was performed in year 23, the optimal residual density was 400 trees per hectare. When the stand quantitative maturity age was reached in year 31, large-sized timber accounted for 76.6% of all trees, and the stand volume was 574.5 m3 per hectare. This thinning strategy is favorable for producing large-sized Chinese fir timber.

[Clinical efficacy of interactive group sandplay versus individual sandplay in the treatment of preschool children with autism spectrum disorder].

OBJECTIVE: To study the clinical efficacy of interactive group sandplay versus individual sandplay in the treatment of preschool children with autism spectrum disorder (ASD). METHODS: A total of 80 ASD children, aged 4-6 years, were enrolled and randomly divided into experimental and control groups, with 40 children in each group. The children in the experimental group joined group sandplay with normal children at a ratio of 1: 3, and those in the control group were treated with individual sandplay. The Aberrant Behavior Checklist (ABC) and Autism Treatment Evaluation Checklist (ATEC) were used to evaluate the treatment outcome after three months of intervention. RESULTS: There were 33 children in the experimental group and 28 in the control group. After three months of intervention, the experimental group had significant reductions in the scores of irritability, social withdrawal, and stereotypic behavior and the total score of the ABC scale (P<0.05), and the control group had significant reductions in the scores of behavior and inappropriate speech and the total score of the ABC scale (P<0.05). Compared with the control group, the experimental group had significantly greater improvements in the score of social withdrawal and the total score of the ABC scale after three months of intervention (P<0.05). After three months of intervention, the experimental group had significant reductions in the scores of sociability, sensory and cognitive awareness, and physical/health behavior and the total score of the ATEC scale (P<0.05), and the control group had significant reductions in the scores of speech, sociability, and physical/health behavior and the total score of the ATEC scale (P<0.05). Compared with the control group, the experimental group had significantly greater improvements in the scores of speech, sociability, and sensory and cognitive awareness and the total score of the ATEC scale after intervention (P<0.01). Compared with the control group, the experimental group also had significantly greater improvements in eye contact and sand stereotyped arrangement (P<0.05). CONCLUSIONS: Both interactive group sandplay and individual sandplay are effective in the treatment of ASD in preschool children. Interactive group sandplay is better than individual sandplay in the treatment of ASD, with significant improvements in sociability, emotion and stereotypic behavior.

[Clinical effect of integrated sandplay therapy in children with Asperger syndrome].

OBJECTIVE: To study the clinical effect of integrated sandplay therapy in preschool children with Asperger syndrome (AS). METHODS: A total of 44 preschool children with AS were randomly divided into an experimental group and a control group, with 22 children in each group. The children in the control group were given routine training, and those in the experimental group were given integrated sandplay therapy in addition to the routine training. The treatment response was assess by the Social Responsiveness Scale (SRS), emotional recognition tools and changes in sandplay theme characteristics after 6 months of treatment. RESULTS: Before intervention, there were no significant differences between the two groups in the total score of SRS, the score of each factor of SRS, and correct rates of facial expression recognition of the upright position, inverted position, upper face and lower face (P>0.05). After 6 months of intervention, both groups had significant reductions in the total score of SRS and the score of each factor of SRS (P<0.01); the control group had significant increases in the correct rates of facial expression recognition of all positions except the upright position (P<0.05), while the experimental group had significant increases in the correct rates of facial expression recognition of all positions (P<0.05). Compared with the control group after intervention, the experimental group had significantly lower total score of SRS and scores of all factors of SRS except social perception (P<0.01) and significantly higher correct rates of facial expression recognition of all positions (P<0.01). The experimental group had a significant change in the number of sandplay theme characteristics after intervention (P<0.01). CONCLUSIONS: Integrated sandplay therapy can improve social responsiveness and emotion recognition ability in preschool children with AS.

Genome-wide association studies for growth and meat production traits in sheep.

BACKGROUND: Growth and meat production traits are significant economic traits in sheep. The aim of the study is to identify candidate genes affecting growth and meat production traits at genome level with high throughput single nucleotide polymorphisms (SNP) genotyping technologies. METHODOLOGY AND RESULTS: Using Illumina OvineSNP50 BeadChip, we performed a GWA study in 329 purebred sheep for 11 growth and meat production traits (birth weight, weaning weight, 6-month weight, eye muscle area, fat thickness, pre-weaning gain, post-weaning gain, daily weight gain, height at withers, chest girth, and shin circumference). After quality control, 319 sheep and 48,198 SNPs were analyzed by TASSEL program in a mixed linear model (MLM). 36 significant SNPs were identified for 7 traits, and 10 of them reached genome-wise significance level for post-weaning gain. Gene annotation was implemented with the latest sheep genome Ovis_aries_v3.1 (released October 2012). More than one-third SNPs (14 out of 36) were located within ovine genes, others were located close to ovine genes (878bp-398,165bp apart). The strongest new finding is 5 genes were thought to be the most crucial candidate genes associated with post-weaning gain: s58995.1 was located within the ovine genes MEF2B and RFXANK, OAR3_84073899.1, OAR3_115712045.1 and OAR9_91721507.1 were located within CAMKMT, TRHDE, and RIPK2 respectively. GRM1, POL, MBD5, UBR2, RPL7 and SMC2 were thought to be the important candidate genes affecting post-weaning gain too. Additionally, 25 genes at chromosome-wise significance level were also forecasted to be the promising genes that influencing sheep growth and meat production traits. CONCLUSIONS: The results will contribute to the similar studies and facilitate the potential utilization of genes involved in growth and meat production traits in sheep in future.

[Differential expression analysis of proteins in neutrophils between clinical mastitis and healthy dairy cows].

Neutrophils provide the first line of defense against invading pathogens and have been reported to play a key role in bovine mammary immune. To examine the differential expression of proteins in neutrophils between clinical mastitis and healthy dairy cows, a 2-dimensional electrophoresis gel map with high repeatability was constructed for bovine neutrophils. From this map, seven differentially expressed proteins were identified by MALDI-TOF MS which are believed to be involved in pathways such as cell metabolism, oxidative stress, and inflammatory reaction. The differentially expressed proteins identified in this study may provide the basis for bovine mastitis resistance breeding research.

[Relationship between gene polymorphism of GABAA receptors gene and childhood autism].

OBJECTIVE: To explore the relationship between gene polymorphism of GABAA receptors and childhood autism by detecting rs140682, rs2081648 and rs140679 site of single nucleotide polymorphism (SNP) in GABAA receptors gene. METHODS: A total of 94 children with autism and 124 normal children were enrolled in a hospital from November 2010 to May 2011. Childhood autism rating scale (CARS) and autism behavior checklist (ABC) were used to evaluate or investigate the case group. After collecting venous blood and extracting the genome DNA, the allele and genotype of SNP rs140682, rs2081648 and rs140679 site in GABAA receptors gene were detected by PCR-RFLP. The allele and genotype of case group and control group were analyzed by χ(2) test, while the score of scales was analyzed by Spearman rank correlation analysis. RESULTS: The age of the case group was 5.12 ± 0.32, and it was 5.25 ± 0.27 in the control group (P < 0.05). In case group, the frequency of genotype CC, CT and TT of rs140682 site was 44, 41 and 9, while it was 48, 65, and 11 in control group (P > 0.05), respectively. The frequency of genotype AA, AG and GG of rs2081648 site was 8, 58 and 28 in case group, while it was 12, 49 and 63 in control group (P < 0.05), respectively. In case group, the frequency of genotype CC, CT and TT of rs140679 site was 15, 36 and 43, while it was 18, 59 and 47 in control group (P > 0.05), respectively. It was revealed by Spearman rank correlation analysis that of rs2081648 site, there was a positive correlation between genotype AG and sensation factor (S), social intercourse factor (R), and language factor (L) of autism behavior checklist (ABC) (r values were 0.149, 0.165 and 0.155, all P values < 0.05). A negative correlation between genotype GG and S, R, L and self-help factor (V) was proved (r values were -0.140, -0.173, -0.158 and -0.135, all P values < 0.05). There was a positive correlation between allele A and R and L factors (r values were 0.153 and 0.137, all P values < 0.05), while a negative correlation between allele G and R and L factors (r values were -0.153 and -0.137, all P values < 0.05). In case group, 42 children were diagnosed with mild-to-moderate autism, while 52 children were severe autism. There was no statistically significant correlation between allele or genotype of SNP rs140682 and rs140679 site and the degree of autism (P > 0.05). There was a positive correlation between allele A and genotype AG and the degree of autism (r values were 0.147 and 0.616, all P values < 0.05), while a negative correlation between allele G and genotype GG and the degree of autism (r values were -0.159 and -0.616, all P values < 0.05). CONCLUSION: The SNP rs2081648 site which located in GABAA receptors gene may be related to autism. No evidence for significant association between rs140682 and rs140679 site and autism was found.

Selection of an effective small interference RNA to silence myostatin gene expression in sheep fibroblast cells.

Myostatin (MSTN), a member of the TGF-ß superfamily, has been identified as a negative regulator of skeletal muscle mass. Inactivating mutations in the MSTN gene are responsible for the development of a hypermuscular phenotype. The aim of this study was to identify an effective small interfering RNA (siRNA) to knockdown the myostatin gene in sheep fibroblast cells. Four siRNAs targeting sheep myostatin were synthesized and tested. Quantitative RT-PCR showed that siRNA1, siRNA2, siRNA3, and siRNA5 significantly reduced myostatin transcript levels by 72, 68, 56, and 76 % (P < 0.05), respectively. Western blot analysis showed that myostatin protein expression was significantly reduced by 76 % using siRNA1 and by 65 % using siRNA5 (P < 0.05). Therefore, siRNA1 and siRNA5 may have the potential to knockdown myostatin gene expression and increase sheep meat production, which should be a focus of future studies.

Association between polymorphisms in the SLC27A1 gene and milk production traits in Chinese Holstein cattle.

We assessed SLC27A1, a candidate gene for milk production traits in Chinese Holstein cattle. DNA was extracted from the blood of 48 top Chinese Holstein Cattle selected according to phenotypic character and mixed into DNA pool for SNP detection. We tested blood samples of these cattle for SNPs in exon 3 and the 3'-flanking region of the SLC27A1 gene by using polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) and DNA sequencing. We found 2 polymorphic sites: 112T>C, a synonymous mutation, in exon 3 (SNP(1)), and 64G>A in the 3'-UTR (SNP(2)). We also determined the genotypes of 330 Chinese Holstein cattle by using PCR-restriction fragment length polymorphism (RFLP). We found 3 genotypes each at SNP(1) (TT, TC, and CC) and SNP(2) (GG, GA, and AA). The association among the different genotypes at these 2 sites and milk production traits was analyzed using a least-squares procedure. The results showed that cows with genotype CC had higher milk yields than those with genotype TC (0.01 < p < 0.05). No significant difference was detected among the 3 SNP(2) genotypes in terms of milk production traits. Our results provide evidence that the C allele have potential effects on milk yield trait.

Alternative splicing and tissue expression of CIB4 gene in sheep testis.

In this study, the sheep CIB4 cDNA was cloned from the small tail Han sheep by RT-PCR and RACE (rapid amplification of cDNA ends), and CIB4 cDNA and amino acid sequence were analyzed. Our results showed that the sheep CIB4 gene expressed two alternatively spliced variants L-CIB4 (long CIB4) and S-CIB4 (short CIB4). Sequence analysis indicated that the sheep CIB4 cDNA cloned (L-CIB4) was 745-bp in length (GenBank accession number: FJ039532) with 185 amino acids residues. The sheep CIB4 cDNA showed more than 72% of sequence identity, at the nucleotide level, to its equivalents in cattle, horse, chimpanzee, humans, mice and rats, while at the deduced protein level, the value increased to 79.6%. Semi-quantitative RT-PCR using total RNA from different tissues showed that CIB4 has a strong tissue-specific expression pattern in sheep. L-CIB4 expression level was shown to be no different in small tail Han sheep and the Dorset ram, but both were significantly different from the Texel (P<0.05). Surprisingly, the short spliced form, S-CIB4, could only be detected in small tail Han sheep, suggesting that CIB4 may be linked in some way to the high fecundity of this breed.