Characterization of the complete mitochondrial genome and phylogenetic analyses of Haemaphysalis tibetensis Hoogstraal, 1965 (Acari: Ixodidae).

Ticks are specialized ectoparasites that feed on blood, causing physical harm to the host and facilitating pathogen transmission. The genus Haemaphysalis contains vectors for numerous infectious agents. These agents cause various diseases in humans and animals. Mitochondrial genome sequences serve as reliable molecular markers, forming a crucial basis for evolutionary analyses, studying species origins, and exploring molecular phylogeny. We extracted mitochondrial genome from the enriched mitochondria of Haemaphysalis tibetensis and obtained a 14,714-bp sequence. The mitochondrial genome consists of 13 protein-coding genes (PCGs), two ribosomal RNA, 22 transfer RNAs (tRNAs), and two control regions. The nucleotide composition of H. tibetensis mitochondrial genome was 38.38 % for A, 9.61 % for G, 39.32 % for T, and 12.69 % for C. The A + T content of H. tibetensis mitochondrial genome was 77.7 %, significantly higher than the G + C content. The repeat units of H. tibetensis exhibited two identical repeat units of 33 bp in length, positioned downstream of nad1 and rrnL genes. Furthermore, phylogenetic analyses based on the 13 PCGs indicated that Haemaphysalis tibetensis (subgenus Allophysalis) formed a monophyletic clade with Haemaphysalis nepalensis (subgenus Herpetobia) and Haemaphysalis danieli (subgenus Allophysalis). Although the species Haemaphysalis inermis, Haemaphysalis kitaokai, Haemaphysalis kolonini, and Haemaphysalis colasbelcouri belong to the subgenus Alloceraea, which were morphologically primitive hemaphysalines just like H. tibetensis, these four tick species cannot form a single clade with H. tibetensis. In this study, the whole mitochondrial genome sequence of H. tibetensis from Tibet was obtained, which enriched the mitochondrial genome data of ticks and provided genetic markers to study the population heredity and molecular evolution of the genus Haemaphysalis.

COVID-19 Case, Death, and Vaccination Rate Disparities by Race and Ethnicity in Virginia.

This paper tracks trends in COVID-19 case, death, and vaccination rate disparities by race and ethnicity in Virginia during the COVID-19 pandemic. COVID-19 case, death, and vaccination rates were obtained from electronic state health department records from March 2020 to February 2022. Rate ratios were then utilized to quantify racial and ethnic disparities for several time periods during the pandemic. The Hispanic population had the highest COVID-19 case and age-adjusted death rates, and the lowest vaccination rates at the beginning of the pandemic in Virginia. These disparities resolved later in the pandemic. COVID-19 case and death rates among the Black population were also higher than those of the White population and these disparities remained throughout the pandemic. Racial and ethnic disparities changed over time in Virginia as vaccination coverage and public health policies evolved. Year 2 of the analysis saw lower case and death rates, and higher vaccination rates for non-White populations in Virginia. Public health strategies need to be addressed during the pandemic and developed before the next pandemic to ensure that large racial and ethnic disparities are not again present at the outset.

Research on Optimization of Post-competition Training Methods for Competitive Sports Athletes / Investigación sobre la optimización de métodos de entrenamiento post-competición para atletas de deportes competitivos

Athletes enter a competitive sport for various reasons and go on to compete for years without any significant modifications that may affect the success of their sporting career. However, there is a cost to this approach of no changes in training strategy. The purpose of this study was to identify successful post-competition training methods by studying both international and Olympic athletes compete in multiple endurance sports during the World Championships event. Results showed several factors including personal characteristics, coaching knowledge, skill level, competition phase and season can have a significant impact on the success rates of athletes following competition performance. In this study, five factors were employed, and the results were published. The information was gathered using a questionnaire from 50 kids who participated in sports. However, the gathered data was subjected to SEM PLS 3 analysis. The findings revealed a favorable relationship between the five variables that were studied.(AU)

Calculation and analysis of quantum radar scattering characteristics of targets in atmospheric medium.

Though much work has been done concerning quantum radar cross section (QRCS), the related question about quantum radar scattering characteristics of targets in the atmospheric medium has not been considered. Understanding this question is of primary significance in the military and civil fields of quantum radar. The main objective of the paper is to propose a new algorithm for the calculation of QRCS in homogeneous atmospheric medium (M-QRCS). Therefore, based on the chain of beam splitters proposed by M. Lanzagorta to describe homogeneous atmospheric medium, the photon attenuation model is established, the photon wave function is modified, and the M-QRCS equation is proposed. Furthermore, in order to obtain an accurate M-QRCS response, we carry out simulation experiments on a flat rectangular plate in the atmospheric medium composed of different atomic arrays. Based on this, we study the influence of the attenuation coefficient, temperature, and visibility on the intensity of the peak value of main lobe and side lobes of M-QRCS. In addition, it is worth noting that the numerical calculation method proposed in this paper is based on the interaction between photons and atoms on the target surface, so it is suitable for the calculation and simulation of M-QRCS for targets of any shape.

Engineered geranyl diphosphate methyltransferase produces 2-methyl-dimethylallyl diphosphate as a noncanonical C6 unit for terpenoid biosynthesis.

Terpenoids constitute the largest class of natural products with complex structures, essential functions, and versatile applications. Creation of new building blocks beyond the conventional five-carbon (C5) units, dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate, expands significantly the chemical space of terpenoids. Structure-guided engineering of an S-adenosylmethionine-dependent geranyl diphosphate (GPP) C2-methyltransferase from Streptomyces coelicolor yielded variants converting DMAPP to a new C6 unit, 2-methyl-DMAPP. Mutation of the Gly residue at the position 202 resulted in a smaller substrate-binding pocket to fit DMAPP instead of its native substrate GPP. Replacement of Phe residue at the position 222 with a Tyr residue contributed to DMAPP binding via hydrogen bond. Furthermore, using Escherichia coli as the chassis, we demonstrated that 2-methyl-DMAPP was accepted as a start unit to generate noncanonical trans- and cis-prenyl diphosphates (C5n+1) and terpenoids. This work provides insights into substrate recognition of prenyl diphosphate methyltransferases, and strategies to diversify terpenoids by expanding the building block portfolio.

Temporal metabolic profiling of erythrocytes in mice infected with Babesia microti.

BACKGROUND: Babesiosis is an emerging zoonosis worldwide that is caused by tick-borne apicomplexans, Babesia spp., which threatens the health of domesticated and wild mammals and even humans. Although it has done serious harm to animal husbandry and public health, the study of Babesia is still progressing slowly. Until now, no effective anti-Babesia vaccines have been available, and administration of combined drugs tends to produce side effects. Therefore, non-targeted metabolomics was employed in the present study to examine the temporal dynamic changes in the metabolic profile of the infected erythrocytes. The goal was to obtain new insight into pathogenesis of Babesia and to explore vaccine candidates or novel drug targets. METHODS: C57BL/6 mice were infected with B. microti and erythrocytes at different time points (0, 3, 6 , 9, 12, and 22-days post-infection) were subjected to parasitemia surveillance and then metabolomics analysis using liquid chromatography-mass spectrometry (LC-MS). Multivariate statistical analyses were performed to clearly separate and identify dysregulated metabolites in Babesia-infected mice. The analyses included principal components analysis (PCA) and orthogonal partial least squares-discrimination analysis (OPLS-DA). The time-series trends of the impacted molecules were analyzed using the R package Mfuzz and the fuzzy clustering principle. The temporal profiling of amino acids, lipids, and nucleotides in blood cells infected with B. microti were also investigated. RESULTS: B. microti infection resulted in a fast increase of parasitemia and serious alteration of the mouse metabolites. Through LC-MS metabolomics analysis, 10,289 substance peaks were detected and annotated to 3,705 components during the analysis period. There were 1,166 dysregulated metabolites, which were classified into 8 clusters according to the temporal trends. Consistent with the trend of parasitemia, the numbers of differential metabolites reached a peak of 525 at 6-days post-infection (dpi). Moreover, the central carbon metabolism in cancer demonstrated the most serious change during the infection process except for that observed at 6 dpi. Sabotage occurred in components involved in the TCA cycle, amino acids, lipids, and nucleotide metabolism. CONCLUSION: Our findings revealed a great alteration in the metabolites of Babesia-infected mice and shed new light on the pathogenesis of B. microti at the metabolic level. The results might lead to novel information about the mechanisms of pathopoiesis, babesisosis, and anti-parasite drug/vaccine development in the future.

Genetic diversity and haplotype analysis of yak and sheep echinococcal cysts isolates from the mitochondrial cox1 gene in parts of Tibet, China.

Echinococcosis, also known as hydatid disease, is caused by the metacestode stage of the species cluster Echinococcus granulosus sensu lato (E. granulosus s.l.). It is almost widespread worldwide, especially in countries and regions dominated by animal husbandry. It is a major parasitic disease that seriously endangers human health, public health safety, environmental safety, and the development of animal husbandry production in western China. In this study, the mitochondrial cox1 gene was used to analyze the genetic diversity and haplotype of bovine and sheep echinococcal cysts isolated in Tibet. Echinococcus granulosus sensu stricto (E. granulosus s.s., G1, G3) was still the dominant species in the infected samples of yak and sheep in some parts of Tibet. Through haplotype analysis, Hap_1 was deemed the dominant haplotype, 14 of the 20 haplotypes were similar to the reference sequence previously published in Genbank, and the rest of the 6 haplotypes were found for the first time. Through Tajima's D value, neutral test Fu's Fs analysis, and haplotype network map, it can be concluded that Echinococcus population expansion has occurred in Xigaze, Tibet. This study provides basic data for understanding the genetic characteristics, epidemiology, and control of echinococcosis in this area.

Development of a Recombinase Polymerase Amplification Assay for Schistosomiasis Japonica Diagnosis in the Experimental Mice and Domestic Goats.

Although the prevalence of schistosomiasis japonica has declined gradually in China, more accurate and sensitive diagnostic methods are urgently needed for the prevention and control of this disease. Molecular diagnostic methods are advantageous in terms of sensitivity and specificity, but they are time-consuming and require expensive instruments and skilled personnel, which limits their application in low-resource settings. In this study, an isothermal DNA amplification assay and recombinase polymerase amplification (RPA) combined with lateral flow dipstick (LFD) were set up. It was used to detect S. japonicum infections in experimental mice and domestic goats by amplifying a specific DNA fragment of S. japonicum. The lower limit of detection for the LFD-RPA assay was evaluated using dilutions of plasmid containing the target sequence. Cross-reactivity was evaluated using genomic DNA from eight other parasites. The effectiveness of the LFD-RPA assay was verified by assessing 36 positive plasma samples and 36 negative plasma samples from mice. The LFD-RPA assay and real-time PCR were also used to assess 48 schistosomiasis japonica-positive plasma samples and 53 negative plasma samples from goats. The LFD-RPA assay could detect 2.6 femtogram (fg) of S. japonicum target DNA (~39 fg genomic DNA of S. japonicum), only 10-fold less sensitive than real-time PCR assay. There was no cross-reactivity with DNA from the other eight parasites, such as Haemonchus contortus and Spirometra. The whole amplification process could be completed within 15 min at 39°C, and the results can be observed easily using the LFD. The sensitivity and specificity of the LFD-RPA assay were 97.22% (35/36, 95% CI, 85.47%-99.93%) and 100% (36/36, 95% CI, 90.26%-100%) in mice, and 93.75% (45/48, 95% CI, 82.80%-98.69%) and 100% (53/53, 95% CI, 93.28%-100%) in goats. By comparison, the sensitivity and specificity of real-time PCR were 100% (36/36, 95% CI, 90.26%-100%) and 100% (36/36, 95% CI, 90.26%-100%) for mice, and 97.92% (47/48, 95% CI, 88.93%-99.95%) and 100% (53/53, 95% CI, 93.28%-100%) for goats. The LFD-RPA assay exhibits high sensitivity and specificity for the diagnosis of schistosomiasis japonica, and it is an alternative method for diagnosis schistosomiasis japonica in low resource setting.

Verification of TRI3 Acetylation of Trichodermol to Trichodermin in the Plant Endophyte Trichoderma taxi.

Trichodermin, a trichothecene first isolated in Trichoderma species, is a sesquiterpenoid antibiotic that exhibits significant inhibitory activity to the growth of many pathogenic fungi such as Candida albicans, Rhizoctonia solani, and Botrytis cinerea by inhibiting the peptidyl transferase involved in eukaryotic protein synthesis. Trichodermin has also been shown to selectively induce cell apoptosis in several cancer cell lines and thus can act as a potential lead compound for developing anticancer therapeutics. The biosynthetic pathway of trichodermin in Trichoderma has been identified, and most of the involved genes have been functionally characterized. An exception is TRI3, which encodes a putative acetyltransferase. Here, we report the identification of a gene cluster that contains seven genes expectedly involved in trichodermin biosynthesis (TRI3, TRI4, TRI6, TRI10, TRI11, TRI12, and TRI14) in the trichodermin-producing endophytic fungus Trichoderma taxi. As in Trichoderma brevicompactum, TRI5 is not included in the cluster. Functional analysis provides evidence that TRI3 acetylates trichodermol, the immediate precursor, to trichodermin. Disruption of TRI3 gene eliminated the inhibition to R. solani by T. taxi culture filtrates and significantly reduced the production of trichodermin but not of trichodermol. Both the inhibitory activity and the trichodermin production were restored when native TRI3 gene was reintroduced into the disruption mutant. Furthermore, a His-tag-purified TRI3 protein, expressed in Escherichia coli, was able to convert trichodermol to trichodermin in the presence of acetyl-CoA. The disruption of TRI3 also resulted in lowered expression of both the upstream biosynthesis TRI genes and the regulator genes. Our data demonstrate that T. taxi TRI3 encodes an acetyltransferase that catalyzes the esterification of the C-4 oxygen atom on trichodermol and thus plays an essential role in trichodermin biosynthesis in this fungus.

The Sur7/PalI family transmembrane protein Tos7 (Yol019w) plays a role in secretion in budding yeast.

Tos7 (Yol019w) is a Sur7/PalI family transmembrane protein in the budding yeast Saccharomyces cerevisiae. Since the deletion of TOS7 did not affect growth or cell morphology, the cellular roles of Tos7 have not been established previously. Here, we show that high-copy TOS7 expression suppressed the growth defect of the secretion-defective RGA1-C term-overexpressing mutant and sec15-1 mutant. Moreover, Tos7 physically interacted with Boi2 and the Rho GTPase Rho3, two key regulators of exocyst assembly, suggesting that Tos7 plays a role in secretion. We also show that the deletion of TOS7 rendered the cells more sensitive to the cell wall-disrupting agents Congo red and calcofluor white while high-copy TOS7 expression had an opposite effect, suggesting that Tos7 affects cell wall organization. Finally, we show that Tos7 localized to punctate patches on the plasma membrane that were largely co-localized with the plasma membrane microdomains named MCC (membrane compartment of Can1). Together, these results suggest that Tos7 contributes to cell surface-related functions. Tos7 is likely an auxiliary component of MCC/eisosome that specifically interacts with the secretory pathway.

Roles of the PH, coiled-coil and SAM domains of the yeast polarity protein Boi2 in polarity-site localization and function in polarized growth.

Boi1 and Boi2 are paralogous proteins essential for bud formation in budding yeast. So far, the domains that target Boi1/Boi2 to the polarity sites and function in bud formation are not well understood. Here, we report that a coiled-coil domain of Boi2 cooperates with the adjacent PH domain to confer Boi2's bud-cortex localization and major function in cell growth. The PH domain portion of the PH-CC bi-domain interacts with the Rho GTPases Cdc42 and Rho3 and both interactions are independent of the GTP/GDP-bound state of each GTPase. Interestingly, high-copy RHO3 and BOI2 but not CDC42 suppressed the growth defect of RGA1-C538 overexpression and the sec15-1 mutant and this BOI2 function depends on RHO3, suggesting that Boi2 may function in the Rho3 pathway. The SAM domain of Boi2 plays an essential role in high-copy suppression of the two mutants as well as in the early bud-neck localization of Boi2. The SAM domain and the CC domain also interact homotypically. They are likely involved in the formation of Boi2-containing protein complex. Our results provide new insights in the localization and function of Boi2 and highlight the importance of the PH-CC bi-domain and the SAM domain in Boi2's localization and function.

An ELISA based on soluble egg antigens for the serodiagnosis of animal schistosomiasis turkestanica.

BACKGROUND: The existing diagnostic techniques for detecting schistosomiasis turkestanica, such as aetiological assays, identify infection by parasitic worms via the incubation of miracidia from faeces or observing eggs under microscopy. However, they are limited in the diagnosis of low-grade and prepatent infections, which lead to a high misdetection rates. Therefore, a new method for parasite diagnosis with increased sensitivity is urgently needed. METHODS: Goats in Nimu County (Tibet, China) infected with Schistosoma turkestanicum in an epidemic area were selected according positivity for the infection by faecal examination. Adult worms were collected, eggs were extracted by the sodium hydroxide (NaOH) erosion method, and soluble worm antigen preparation (SWAP) and soluble egg antigen (SEA) were isolated. The best coating concentration of the antigens and the best degree of dilution for serum were determined by square array experiments, and the optimal blocking solution and serum diluents were selected. The specificity, sensitivity and crossover of the ELISA method were determined using 48 samples of goat sera positive for S. turkestanicum, 100 samples of goat sera negative for S. turkestanicum, and 54 samples of buffalo sera positive for S. japonicum. Serological assays were established with samples from goats naturally grazed in a rural area of Nimu County, Tibet Province, by using the indirect ELISA method for the diagnosis of schistosomiasis, and faeces were collected for miracidia hatching. The sensitivity of the two detection methods was compared. RESULTS: Eggs of S. turkestanicum were distributed in the host duodenum and small intestine. Eggs in the host intestinal wall were extracted by the NaOH erosion method, which provided intact eggs with reduced impurities. The testing results obtained by isolating SEA were more stable than those obtained by using SWAP and less affected by the coating concentration and serum dilution. Additionally, the value of positive serum/negative (P/N) serum for SEA was much higher than that for SWAP. The optimal coating concentration of SEA was 0.5 µg/ml, and the optimal serum dilution was 1:100. The specificity and sensitivity of the indirect ELISA based on SEA (S. turkestanicum) were both 100%, and no cross-reactivity was found with schistosomiasis japonica. An epidemiological survey of goats in naturally infected areas showed that the prevalence rate of schistosomiasis turkestanica was 93%, and the infection rate increased with the ages of the goats. CONCLUSION: We aimed to develop a sensitive method to utilize in the mass field screening of livestock. As a diagnostic antigen, SEA (S. turkestanicum) was more suitable for serological testing than SWAP (S. turkestanicum). The indirect ELISA using SEA (S. turkestanicum) exhibited good sensitivity, specificity and no cross-reactivity with schistosomiasis japonica. The degree of infectivity and prevalence of S. turkestanicum infection in endemic areas are serious and should be a focus of concern among local departments.

Genetic variation of Echinococcus spp. in yaks and sheep in the Tibet Autonomous Region of China based on mitochondrial DNA.

BACKGROUND: Cystic echinococcosis (CE) in humans and livestock is caused by Echinococcus granulosus (sensu lato). In China where CE is endemic, a number of studies have shown that Echinococcus granulosus (sensu stricto) is majorly responsible for CE. However, E. canadensis (G6) which is the second leading cause of CE is now being detected in most parts of the country. In this study, the species diversity and genetic variation of Echinococcus granulosus (s.l.) in four counties in Tibet Autonomous Region of China were investigated. METHODS: Infection with Echinococcus granulosus (s.s.) in yaks and sheep was identified using NADH dehydrogenase subunit 1 and 5 (nad1 and nad5) mitochondrial genes while the genotype G6 of E. canadensis initially diagnosed with NADH dehydrogenase subunit 1 (nad1) was further confirmed by analysis of the complete mitochondrial genome and a phylogenetic network constructed based on the nad2 and nad5 genes. RESULTS: Out of 85 hydatid cyst samples collected from slaughtered sheep (n = 54) and yaks (n = 31), 83 were identified as E. granulosus (s.s.) G1 (n = 77), G3 (n = 6) and 2 were identified as E. canadensis G6. Analysis of the nad1/nad5 genes revealed 16/17 mutations with 9/14 parsimony informative sites resulting in 15/14 haplotypes, respectively. Haplotype diversity (Hd) and nucleotide diversity (π) of E. granulosus (s.s.) population were 0.650 and 0.00127 for nad1 and 0.782 and 0.00306 for nad5, respectively, with an overall negative Tajima's D and Fu's Fs. A low FST indicated no genetic difference between isolates from sheep and yaks. CONCLUSION: Pockets of infection with E. canadensis (G6, G7, G8 and G10) have been previously reported in sheep, goats, yaks and/or humans in different parts of China. While the G6 genotype has been previously reported in sheep in the Tibet Autonomous Region, the detection in a yak in the present study represents the first to the best of our knowledge. Therefore, we recommend future surveys and control efforts to comprehensively investigate other potential intermediate hosts for the prevalence and genetic diversity of the E. canadensis group (G6, G7, G8 and G10) across the country and their inclusion into the existing CE control programme.

Prevalence and genetic characterization of Enterocytozoon bieneusi and Giardia duodenalis in Tibetan pigs in Tibet, China.

Enterocytozoon bieneusi and Giardia duodenalis are important opportunistic enteric zoonotic pathogens that cause diarrhoea and intestinal diseases in animals and humans. China is the largest producer of pigs, but whether Tibetan pigs, a unique pig breed in Tibet, are infected with E. bieneusi and G. duodenalis is unknown. Therefore, we conducted a molecular epidemiological survey to determine the prevalence of E. bieneusi and G. duodenalis in Tibetan pigs in Tibet, China, and identified the genotypes of these causative agents. A total of 345 faecal specimens were collected from Tibetan pigs from three Tibet counties (Milin, Cuona and Gongbujiangda), examined by nested PCR and sequenced utilizing genetic markers in the ribosomal internal transcribed spacer (ITS) region of the rRNA and glutamate dehydrogenase (gdh) gene for E. bieneusi and G. duodenalis, respectively. Moreover, using multilocus sequence typing, the subtypes of E. bieneusi were identified based on four loci (MS1, MS3, MS4 and MS7). A total of 41 (11.88%) faecal samples from Tibetan pigs were E. bieneusi-positive, and 2 (0.58%) were G. duodenalis-positive. The multivariate logistic regression analysis showed that age was considered a risk factor for Tibetan pig infection of E. bieneusi. Two novel (GB11, GB31) and four known E. bieneusi genotypes (EbpC, EbpD, PigEBITS5 and CHS12) were identified and were all classified as zoonotic group 1 according to the phylogenetic analysis. Two MLGs (MLGI and MLGII) were further identified in the E. bieneusi EbpC genotype by multilocus sequence typing analysis. In addition, two G. duodenalis assemblages (D and E) were found in the present study. To our knowledge, the current study is the first to detect the prevalence and perform genetic characterization of G. duodenalis in Tibetan pigs in Tibet, China. The results could provide essential data for controlling E. bieneusi and G. duodenalis infections in Tibetan pigs that are in contact with other animals and humans, as Tibetan pigs could be a potential source for human infection by these pathogens.

Identification and characterization of new Muscodor endophytes from gramineous plants in Xishuangbanna, China.

The endophytic fungi Muscodor spp. produce volatile organic compounds (VOCs) which can inhibit and even kill pathogenic fungi, bacteria, and nematodes. Nine endophytic fungal strains, isolated from the shoots of gramineous plants including Arthraxon hispidus, Eleusine indica, Oplismenus undulatifolius, and Oryza granulata, were identified as Muscodor through phylogenetic analysis of the internal transcribed spacer. Through an SPSS K-means cluster analysis, the nine Muscodor strains were divided into four groups based on the antifungal activities of the VOCs produced by these fungi determined by a two-section confrontation test. The first group contains the strains Y-L-54, W-S-41, Y-S-35, W-T-27, and Y-L-56, which showed the strongest activity. The second and third groups contain W-S-35 and Y-L-43, which showed stronger and moderate activity, respectively. The fourth group contains W-S-38 and N-L-7, which were the weakest in inhibiting the tested pathogens. Thirty-five compounds and the relative amounts of VOCs were determined by SPME-GC-MS and comparison with the NIST14 mass spectrometry database and Agilent MassHunter qualitative and quantitative analyses. These 35 compounds were classified into two different categories: (a) the product of fatty acid degradation, and (b) the intermediate and final metabolite of the metabolic pathway with the precursor of mevalonic acid. SPSS clustering analysis showed that the chemical components of VOCs might be correlated with their bioactivity rather than their phylogenetic assignment and some of the identified compounds might be responsible for antifungal activity. In conclusion, new Muscodor endophytes were recorded in tropical gramineous plants and a number of strains showed remarkable bioactive properties. Therefore, they have important potential applications in the fields of plant disease control.

Multi-Complementary Model for Long-Term Tracking.

In recent years, video target tracking algorithms have been widely used. However, many tracking algorithms do not achieve satisfactory performance, especially when dealing with problems such as object occlusions, background clutters, motion blur, low illumination color images, and sudden illumination changes in real scenes. In this paper, we incorporate an object model based on contour information into a Staple tracker that combines the correlation filter model and color model to greatly improve the tracking robustness. Since each model is responsible for tracking specific features, the three complementary models combine for more robust tracking. In addition, we propose an efficient object detection model with contour and color histogram features, which has good detection performance and better detection efficiency compared to the traditional target detection algorithm. Finally, we optimize the traditional scale calculation, which greatly improves the tracking execution speed. We evaluate our tracker on the Object Tracking Benchmarks 2013 (OTB-13) and Object Tracking Benchmarks 2015 (OTB-15) benchmark datasets. With the OTB-13 benchmark datasets, our algorithm is improved by 4.8%, 9.6%, and 10.9% on the success plots of OPE, TRE and SRE, respectively, in contrast to another classic LCT (Long-term Correlation Tracking) algorithm. On the OTB-15 benchmark datasets, when compared with the LCT algorithm, our algorithm achieves 10.4%, 12.5%, and 16.1% improvement on the success plots of OPE, TRE, and SRE, respectively. At the same time, it needs to be emphasized that, due to the high computational efficiency of the color model and the object detection model using efficient data structures, and the speed advantage of the correlation filters, our tracking algorithm could still achieve good tracking speed.

Echinochloa crus-galli genome analysis provides insight into its adaptation and invasiveness as a weed.

Barnyardgrass (Echinochloa crus-galli) is a pernicious weed in agricultural fields worldwide. The molecular mechanisms underlying its success in the absence of human intervention are presently unknown. Here we report a draft genome sequence of the hexaploid species E. crus-galli, i.e., a 1.27 Gb assembly representing 90.7% of the predicted genome size. An extremely large repertoire of genes encoding cytochrome P450 monooxygenases and glutathione S-transferases associated with detoxification are found. Two gene clusters involved in the biosynthesis of an allelochemical 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) and a phytoalexin momilactone A are found in the E. crus-galli genome, respectively. The allelochemical DIMBOA gene cluster is activated in response to co-cultivation with rice, while the phytoalexin momilactone A gene cluster specifically to infection by pathogenic Pyricularia oryzae. Our results provide a new understanding of the molecular mechanisms underlying the extreme adaptation of the weed.

[Helminth Infections in Goats in Nimu County of Tibet].

Postmortem examinations were made in 99 goats in Nimu County of Tibe, and parasites were collected and identified based on morphology. The collected parasites were categorized, and infection status was analyzed. The helminth infection rate was 100% among the goats, and all showed a pattern of mixed infection. The identified parasites belonged to 21 species, 15 genera, and 9 families. The Trichuris genus（36.4%） was the most prevailing among nematodes in the gastrointestinal tract; Paramphistomum cervi（60.6%） and Paramphistomum gotoi（60.6%） were predominant among trematodes detected; Cysticercus tenuicollis（52.5%） was the predominant cestode detected; and Orientobilharzia turkestanicum was the major parasite detected in the portal vein (69.7%).

Comparative Study on the Genetic Diversity of GHR Gene in Tibetan Cattle and Holstein Cows.

Due to the phenotype-based artificial selection in domestic cattle, the underlying functional genes may be indirectly selected and show decreasing diversity in theory. The growth hormone receptor (GHR) gene has been widely proposed to significantly associate with critical economic traits in cattle. In the present study, we comparatively studied the genetic diversity of GHR in Tibetan cattle (a traditional unselected breed, n = 93) and Chinese Holstein cow (the intensively selected breed, n = 94). The Tibetan yak (n = 38) was also included as an outgroup breed. A total of 21 variants were detected by sequencing 1279 bp genomic fragments encompassing the largest exon 9. Twelve haplotypes (H1∼H12) constructed by 15 coding SNPs were presented as a star-like network profile, in which haplotype H2 was located at the central position and almost occupied by Tibetan yaks. Furthermore, H2 was also identical to the formerly reported sequence specific to African cattle. Only haplotype H5 was simultaneously shared by all three breeds. Tibetan cattle showed higher nucleotide diversity (0.00215 ± 0.00015) and haplotype diversity (0.678 ± 0.026) than Holstein cow. Conclusively, we found Tibetan cattle have retained relatively high genetic variation of GHR. The predominant presence of African cattle specific H2 in the outgroup yak breed would highlight its ancestral relationship, which may be used as one informative molecular marker in the phylogenetic studies.

Effect of immunization against GnRH on hypothalamic and testicular function in rams.

The objective was to determine effects of active immunization against GnRH on reproductive function in Tibetan rams. Peripubertal Tibetan rams (n = 30) were randomly and equally allocated into three groups: control (no treatment); surgically castrated; or immunized against 100-µg d-Lys6-GnRH-tandem-dimer peptide conjugated to ovalbumin in Specol adjuvant at 24 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 4-week intervals until rams were killed (40 weeks). Immunization triggered a good antibody response in all immunized rams (P < 0.01). Compared with intact controls, anti-GnRH immunization reduced (P < 0.01) serum concentrations of testosterone, inhibin A, LH, and FSH, and it induced testicular atrophy (suppression of spermatogenesis). Androstenone concentrations in fat tissues of GnRH-immunized rams were also rendered nondetectable (P < 0.001). Furthermore, mRNA expressions of GnRH receptor, LH-ß, and FSH-ß in the pituitary and of LH receptor, FSH receptor, and inhibin α and ßA subunits in the testes were decreased in immunized rams compared with intact controls (P < 0.05). This was apparently the first report that active immunization against GnRH-tandem-dimer-ovalbumin conjugate in Specol adjuvant was an effective alternative to surgical castration for Tibetan rams under practical Tibetan plateau conditions.