• Title/Summary/Keyword: Population suppression

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Weed control treated with salt and seawater in organic agricultural upland

  • Lee, Sang-Beom;Lee, M.H.;Kang, C.K.;Kim, M.S.;Nam, H.S.
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.295-297
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    • 2011
  • Weed control is the most important issue in organic farming systems that limit crop growth and their yield. Field experiments were conducted in organic soybean (Glycine max Merrill) to evaluate the weed suppression effects of salt and seawater treatment. Weed population and fresh weight were monitored after 6 weeks of salt and seawater treatments. The most important weeds were Digitaria sanguinalis, Portulaca oleracea, Tradescantia reflexa and Chenopodium album var. centrorubrum, but also 6 other species were observed in soybean arable field. Soybean crops under seawater or their solids application were well grown. The results treated with salts and seawater indicate decreases by 13.4~30.8% in weed density and by 18.0~43.2% in their fresh weight and soil hardness increases of up to 2.1-fold. Salt and seawater provided good additional weed control, but they were caused a serious problem in deterioration of soil physical properties.

Effects of intravenous multiple busulfan injection on suppression of endogenous spermatogenesis in recipient stallion testes

  • Jung, Heejun;Yoon, Minjung
    • Journal of Animal Science and Technology
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    • v.63 no.5
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    • pp.1194-1203
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    • 2021
  • Preparation of recipient stallions is critical step to produce donor spermatogonial stem cell (SSC) derived sperm using transplantation technique. This study was conducted to evaluate the effects of intravenous busulfan infusion on germ cell depletion, semen production, and libido in stallions. Six Thoroughbred stallions were separated into two treatment groups: 1) a multiple low-dose (2.5 mg/kg bw for the first 4 weeks and 5 mg/kg bw for the 5th week); and 2) control group treated with PBS. Testicular samples were obtained at 11 weeks and classified into three different patterns of spermatogenesis, such as normal, Sertoli cell only, and destroyed. Semen collection and libido experiments were performed 1 week before treatment, and 4 and 8 weeks after treatment. For the sperm analysis, total spermatozoa and motility were measured using a light microscope with a motility analyzing system. In the multiple low-dose group, the numbers of tubules categorized as Sertoli cell only were significantly higher than those in the control as well as the total population and total/progressive motility of sperm were significantly decreased 8 weeks after the start of the treatment. The sperm production and motility in the multiple low-dose group appears to be reduced, while libido was maintained. In conclusion, multiple administration of 2.5 mg/kg bw busulfan depletes endogenous germ cells in the stallion recipients for SSC transplantation.

Synthetic Homoisoflavane Derivatives of Cremastranone Suppress Growth of Colorectal Cancer Cells through Cell Cycle Arrest and Induction of Apoptosis

  • Shin, Ha-Eun;Lee, Seul;Choi, Yeram;Park, Sangkyu;Kwon, Sangil;Choi, Jun-Kyu;Seo, Seung-Yong;Lee, Younghee
    • Biomolecules & Therapeutics
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    • v.30 no.6
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    • pp.576-584
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    • 2022
  • Colorectal cancer is diagnosed as the third most prevalent cancer; thus, effective therapeutic agents are urgently required. In this study, we synthesized six homoisoflavane derivatives of cremastranone and investigated their cytotoxic effects on the human colorectal cancer cell lines HCT116 and LoVo. We further examined the related mechanisms of action using two of the potent compounds, SH-19027 and SHA-035. They substantially reduced the cell viability and proliferation in a dose-dependent manner. Treatment with SH-19027 and SHA-035 induced cell cycle arrest at the G2/M phase and increased expression of p21 both of which are implicated in cell cycle control. In addition, the apoptotic cell population and apoptosis-associated marker expression were accordingly increased. These results suggest that the synthesized cremastranone derivatives have anticancer effects through the suppression of cell proliferation and induction of apoptosis. Therefore, the synthesized cremastranone derivatives could be applied as novel therapeutic agents against colorectal cancer.

Adherence to antiretroviral therapy and associated factors among HIV-positive adolescents in Sub-Saharan Africa: a systematic review

  • Gebre Gelana Gudisa;Sangeun Jun
    • Journal of Korean Biological Nursing Science
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    • v.25 no.4
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    • pp.266-275
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    • 2023
  • Purpose: Although long-term viral suppression and antiretroviral therapy (ART) success depend on sustained adherence, adolescents' adherence rates are suboptimal. Optimal adherence is influenced by various factors. Since Sub-Saharan Africa is home to over 80% of adolescents living with human immunodeficiency virus (HIV) and considering their unique characteristics and susceptibility to poor adherence, it is crucial to provide updated knowledge on adherence rates and their determinants among this population. This review aims to present up-to-date data on adherence rates and associated factors among HIV-positive adolescents in Sub-Saharan Africa. Methods: A systematic review was conducted following the PRISMA guidelines. The PubMed and Scopus databases were used to identify documents corresponding to the study's objectives. Eleven studies were included in this review after being selected from among all studies that were found online from 2017 to 2023. Results: The reported adherence rates ranged from 55% to 86%. In total, 32 factors were found to be related to adherence among HIV-positive adolescents in Sub-Saharan Africa. These included 12 adherence-facilitating factors and 20 adherence-inhibiting factors. The most often mentioned factors affecting adherence were advanced World Health Organization clinical stage (i.e., stage IV), ART dose and regimens, a lack of support, and violence victimization. Conclusion: Our findings can help healthcare providers collaborate with HIV-positive adolescents to improve ART adherence and ensure the best possible health outcomes.

The pathophysiology of diabetic foot: a narrative review

  • Jiyoun Kim
    • Journal of Yeungnam Medical Science
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    • v.40 no.4
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    • pp.328-334
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    • 2023
  • An aging population and changes in dietary habits have increased the incidence of diabetes, resulting in complications such as diabetic foot ulcers (DFUs). DFUs can lead to serious disabilities, substantial reductions in patient quality of life, and high financial costs for society. By understanding the etiology and pathophysiology of DFUs, their occurrence can be prevented and managed more effectively. The pathophysiology of DFUs involves metabolic dysfunction, diabetic immunopathy, diabetic neuropathy, and angiopathy. The processes by which hyperglycemia causes peripheral nerve damage are related to adenosine triphosphate deficiency, the polyol pathway, oxidative stress, protein kinase C activity, and proinflammatory processes. In the context of hyperglycemia, the suppression of endothelial nitric oxide production leads to microcirculation atherosclerosis, heightened inflammation, and abnormal intimal growth. Diabetic neuropathy involves sensory, motor, and autonomic neuropathies. The interaction between these neuropathies forms a callus that leads to subcutaneous hemorrhage and skin ulcers. Hyperglycemia causes peripheral vascular changes that result in endothelial cell dysfunction and decreased vasodilator secretion, leading to ischemia. The interplay among these four preceding pathophysiological factors fosters the development and progression of infections in individuals with diabetes. Charcot neuroarthropathy is a chronic and progressive degenerative arthropathy characterized by heightened blood flow, increased calcium dissolution, and repeated minor trauma to insensate joints. Directly and comprehensively addressing the pathogenesis of DFUs could pave the way for the development of innovative treatment approaches with the potential to avoid the most serious complications, including major amputations.

Competition between Transplanted Lowland Rice and Weeds as Affected by Plant Spacing and Rice Cultivar Having Different Culm Length (수도품종(水稻品種)의 간장차이(稈長差異)가 잡초(雜草)와의 경쟁력(競爭力)에 미치는 영향(影響))

  • Kim, S.C.;Lee, S.K.;Park, R.K.
    • Korean Journal of Weed Science
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    • v.1 no.1
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    • pp.44-51
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    • 1981
  • An experiment was conducted to obtain the basic information about competitive ability of rice against weeds as affected by culm length at the Yeongnam Crop Experiment Station, Office of Rural Development in 1980. More weeds were harvested from the plot of short statured cultivar, Manseogbyeo compared to the plot of Cheongcheongbyeo that was approximately 10cm taller than Manseogbyeo regardless of planting density variables. Weeds also decreased as rice population increased from $30{\times}15cm$, $40{\times}(10{\times}10cm)$ and to $10{\times}10cm$, in order. The degree of weed suppression and floristic composition was varied depending upon plant spacing and weeding regime subjected at the previous year. The degree of weed suppression became increased with increasing rice population. The degree of weed suppression at the $10{\times}10cm$ plant spacing showed as high as hand weeding subjected in the previous year. However, in terms of floristic composition, Scirpus hotarui Roxb. became dominant when rice had cultivated at $10{\times}10cm$ plant spacing in the previous year while S. hotarui and Sagittaria pygmaea Miq. were both important in the hand weeding plot. The highest grain yield of rice showed at the $10{\times}10cm$ plant spacing while no significant difference was observed between $40{\times}(10{\times}10cm)$ and $30{\times}15cm$ plant spacings for both weeding regimes and both cultivars. However, response of grain yield to weeding regime was differed in two cultivars. For Manseobgyeo, significant grain yield decreased in no weeding plot regardless of plant spacing variables. But in case of Cheongcheongbyeo, grain yield reduction was only recognized at the $30{\times}15cm$ plant spacing. Based on these result it could be concluded that Cheongcheongbyeo (10cm taller in height) seemed to be more competitive against weeds than Manseogbyeo.

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Biological Control of Polyphagotarsonenmus latus(Acari: Tasonemidae) by Amblyseius cucumeris(Acari: Phytoseiidae) (오이이리응애(Amblyseius cucumeris)를 이용한 차먼지응애(Polyphagotarsonemus latus) 생물적 방제)

  • La, Seung-Yong;Paik, Chae-Hoon;Lee, Geon-Hwi;Kim, Doo-Ho
    • Korean journal of applied entomology
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    • v.48 no.3
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    • pp.347-354
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    • 2009
  • This study was conducted on the biological control effects of the natural enemy, Amblyseius cucumeris, against Polyphagotarsonemus latus. The broad mite moved to a new habitat after the carrying capacity of the preferred habitat on the upper leaf has been reached. Population dynamics between predator, Amblyseius cucumeris, and prey, P. latus, were quite well synchronized since the predator followed the movement of the prey. In predation test by Amblyseius cucumeris on P. latus, A. cucumeris fed on 8.8, 15.2, 27.0 and 30.3 individuals/day under the temperatures of 15, 20, 25, and $30^{\circ}C$, respectively. The A. cucumeris larva, protonymph, deutonymph, adult male, and adult female fed on 0.5, 1.6, 5.2, 3.8, and 27 individuals of adult P. latus per day, respectively, under $25^{\circ}C$ condition. The functional response curve of adult P. latus to the densities of A. cucumeris showed Holling's Type II curve. The consumption of prey by A. cucumeris increased with the prey density increase, but the consumption rate decreased. The critical ratio of predator vs. prey effectively to suppress (98% over) the population of P. latus by releasing A. cucumeris was 1:40 on red pepper.

Lack of Association of Intron 3 16 bp Polymorphism of TP53 with Breast Cancer among Iranian-Azeri Patients

  • Pouladi, Nasser;Kouhsari, Shideh Montasser;Feizi, Mohammadali Hosseinpour;Dehghan, Roghayeh;Azarfam, Parvin;Farajzadeh, Davoud
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2631-2634
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    • 2014
  • Background: p53 gene is a well-known tumor suppressor gene that has several polymorphisms in both its exons and introns. It has been suggested that intron 3 16 bp duplication polymorphism may affect the gene function resulting in reduction or suppression of p53 anti tumor activity. In most case control studies a duplicated allele has been noticeably more frequent in cases rather than controls but there are also conflicting results. The aim of this study was to assess the association of intron 3 16 bp duplication polymorphism of p53 with breast cancer risk among Iranian-Azeri population. We also analyzed the clinicopathological information of patients as an epidemiological description of breast cancer in the north-west of Iran. Materials and Methods: This case-control study was performed on 221 breast cancer patients and 170 controls. Genomic DNA was extracted from peripheral blood samples and tumor tissues. p53 PIN3 genotype was determined using electrophoresis of PCR products on 8% non-denaturing polyacrylamide gels and silver staining. Results: In the control and case groups, respectively, 62.9% and 61.1% had no 16 bp insertion (A1A1 genotype), 7.1% and 7.7% had insertion in both p53 alleles (A2A2) and 30% and 31.2% were heterozygous (A1A2). There was no significant difference between genotype frequencies as well as allelic frequencies in two case and control groups. Conclusions: According to the result of the present study, the intron 3 16 bp duplication polymorphism of p53 could not be assessed as a marker of risk factor for predisposition to breast cancer in Azeri population. However, a high frequency of A2 allele (22.1%) in our population suggested that intron 3 16 bp duplication polymorphism may be a valuable marker for study in other cancers with well designed large groups.

Rhizosphere Inhibition of Cucumber Fusarium Wilt by Different Surfactinexcreting Strains of Bacillus subtilis

  • Jia, Ke;Gao, Yu-Han;Huang, Xiao-Qin;Guo, Rong-Jun;Li, Shi-Dong
    • The Plant Pathology Journal
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    • v.31 no.2
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    • pp.140-151
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    • 2015
  • Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of $0.96log_{10}ng/g$ to $2.39log_{10}ng/g$ was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of $2.91log_{10}ng/g$ to $3.36log_{10}ng/g$ at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field.

Prey Consumption and Suppression of Vegetable Aphids by Chrysopa pallens (Neuroptera: Chrysopidae) as a Predator (채소류 진딧물에 대한 칠성풀잠자리붙이의 포식량 및 밀도억제 효과)

  • 이건휘;이승찬;최남영;김두호
    • Korean journal of applied entomology
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    • v.39 no.4
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    • pp.251-258
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    • 2000
  • These studies were conducted to investigate the prey consumption and suppression of cotton aphid and green peach aphid by Chrysopa pallens Ramber as a predator. The 3$^{rd}$ instar of C. pallets fed on 29.8, 77.9, 133.6, and 155.7 individuals of apterous Aphis goussypii Glover a day at 17,22, 27, and 32$^{\circ}C$, respectively. A preovipositing female fed on 73.1 individuals, ovipositing female on 86.6 individuals, and adult male on 69.7 individuals of apterous Myzus persicae (Sulzer) a day at the 27$^{\circ}C$. The functional response curve of the larvae and adults of C. pallens to the densities of A. gossypii indicated Helling’s Type II: the consumption of prey by the C. pallens increased with the prey density but the consumption rate decreased. The attack rate of 3rd instar of C. pallens was the highest among the 2nd instar, 3$^{rd}$ instar, adult male and adult female, and handling time was the shortest. The critical ratio of the predator vs. the prey to effectively suppress the population of A. gossypii by releasing C. pallets eggs was 1 : 4 on red pepper and egg plant, and 1 : 3 on cucumber. Release of second larval stave of C. pallens at the ratio of 1 : 30 of the predator vs. the prey controlled satisfactorily A. gossypii on red pepper, and 1 : 20 on cucumber and tomato. The three-times introduction of the eggs of C. pallens was as effective as four applications of insecticides from mid-June to late September.r.

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