山东省临沂地区杨树人工林地位指数表的编制

山东省临沂地区杨树人工林地位指数表是于1986年冬至1987年春,收集了25株69杨、72杨和健杨优势木树干解析和104块临时标地材料编制而成。选用lgH=a+b(1/A)公式为导向曲线数学模型;标准年龄定为8a;指数级距2m;级数8个(12—26m)。采用树高相对值法导出各指数级各年龄树高值,经检验此法精度较高,符合生长快、伐期短的杨树生长规律,可供该地区林业部门试用。     

Acceleration of emergence of bacterial antibiotic resistance in connected microenvironments

The emergence of bacterial antibiotic resistance is a growing problem, yet the variables that influence the rate of emergence of resistance are not well understood. In a microfluidic device designed to mimic naturally occurring bacterial niches, resistance of Escherichia coli to the antibiotic ciprofloxacin developed within 10 hours. Resistance emerged with as few as 100 bacteria in the initial inoculation. Whole-genome sequencing of the resistant organisms revealed that four functional single-nucleotide polymorphisms attained fixation. Knowledge about the rapid emergence of antibiotic resistance in the heterogeneous conditions within the mammalian body may be helpful in understanding the emergence of drug resistance during cancer chemotherapy.     

Maturation and spawning performance of pond-reared Penaeus merguiensis in different combinations of temperature, light intensity and photoperiod

The combined effects of temperature (23 and 27 °C), light intensity (1100 and 2 lux or ≈ 21.5 and 0.04 μEinst m^?2 s respectively) and photoperiod (10 h light/14 h dark and 14 h light/10 h dark) on ovarian maturation and spawning performance of ablated pond‐reared Penaeus merguiensis were investigated in a 51‐day experiment. The results showed that temperature was the most influential factor, followed by light intensity, whereas the effect of photoperiod was minor. As the maturation process progressed, the effects of temperature and light intensity became stronger while that of photoperiod became less significant. Temperature significantly affected all the reproductive parameters assessed. Prawns in the 27 °C treatments outperformed those in the 23 °C treatments (P < 0.05). The effect of light intensity was found to have a significant effect (P < 0.05) only on the proportion of spawners (prawns that spawned) and spawning rate. More prawns spawned at a higher rate under dim light (2 lux) than under strong light (1100 lux). Photoperiod affected only the proportion of prawns reaching stage III of ovarian development (P < 0.05). There were interactions between temperature and light intensity affecting the proportion of prawns reaching stage III and, although not significantly, the proportion of spawners (P = 0.177), fecundity (P = 0.134) and survival (P = 0.061). Overall, it is recommended that a combination of 27 °C, 2 lux and 10 h light/14 h dark is suitable for the maturation of pond‐reared P. merguiensis. There were indications that temperature can be used to control the rate of ovarian maturation. Also, it is possible to increase light intensity up to 1100 lux in P. merguiensis hatcheries if prawns are ablated.     

Cold tolerance of the banana prawn Penaeus merguiensis de Man and its growth at different temperatures

Critical thermal minima (CTMin) were determined for subadults of Penaeus merguiensis acclimated at 15, 18, 21 and 24 °C for 3 weeks. The effect of cooling rate on CTMin was also investigated. The CTMin of prawns from these respective acclimation groups were 5.3, 6.0, 7.4, 9.0 and 4.7, 5.4, 6.0, 7.3 °C at the cooling rate of 1 °C h^?1 and 3 °C h^?1 respectively. Both acclimation temperature and cooling rate had a significant effect (P < 0.01) on the CTMin. Observation during the acclimation period showed that the growth rate of prawns acclimated at 24 °C was much higher than those acclimated at 21, 18 and 15 °C. The results indicate that P. merguiensis can overwinter in aquaculture ponds in south‐east Queensland, Australia, or other subtropical areas and attain good growth if simple overwintering facilities are available.     

Simulating and mapping agricultural land productivity: An application to Macadamia nut

A procedure for simulating and mapping land productivity was developed. The procedure used only existing data such as soil surveys based on soil taxonomy, weather records and yield either from published sources or collected from producers. It provides a means of assessing quantitatively the likelihood of introducing new crops to a region. The need to estimate benefits from crop inputs modification such as irrigation and fertilizer can also be met by this procedure. It can also be used to help select crop performance test sites for maximum extrapolation of test results to a large area.     

Evaluation of the influence of prostaglandin E2 on recombinant equine interleukin-1beta-stimulated matrix metalloproteinases 1, 3, and 13 and tissue inhibitor of matrix metalloproteinase 1 expression in equine chondrocyte cultures

OBJECTIVE: To determine the effects of prostaglandin E2 (PGE2) on recombinant equine interleukin (IL)-1beta-stimulated expression of matrix metalloproteinases (MMP 1, MMP 3, MMP 13) and tissue inhibitor of matrix metalloproteinase 1 (TIMP 1) in vitro. SAMPLE POPULATION: Cultured equine chondrocytes. PROCEDURE: Stationary monolayers of first-passage chondrocytes were exposed to graduated concentrations of PGE2 with or without a subsaturating dose (50 pg/ml) of recombinant equine IL-1beta (reIL-1beta) to induce expression of MMP 1, MMP 3, MMP 13, and TIMP 1, followed by RNA isolation and northern blotting. In subsequent experiments, gene expression was similarly quantified from mRNA isolated from cultures pretreated with phenylbutazone to quench endogenous PGE2 synthesis, followed by exposure to reIL-1beta and exogenous PGE2 (5 mg/ml) with appropriate controls. RESULTS: Exogenous PGE2 (10 mg/ml) significantly reduced reIL-1beta-induced expression of MMP 1, MMP 3, MMP 13, and TIMP 1. Abrogation of cytokine induction with this dose of PGE2 was comparable to that for dexamethasone (10(-5) M) control. Similarly, pretreatment with phenylbutazone, followed by exposure to relL-1beta and PGE2 (5 mg/ml), was associated with a reduced expression of the genes of interest, an effect that was significant for MMP 1, MMP 13, and TIMP 1. CONCLUSIONS AND CLINICAL RELEVANCE: The MMP and TIMP 1 are important mediators in the pathophysiologic events in osteoarthritis. The potential for physiologically relevant regulation of expression of these genes by PGE2 is a consideration in the use of drugs that inhibit prostanoid synthesis in the treatment of equine arthropathies.     

枣树桃小食心虫(Carposina niponensis Walsingham)发生规律及防治研究

据1962—1963年两年的研究,桃小食心虫在乐陵棗区一年发生1—2代。第二代发生数量多少与当年整个发生期的早晚有密切的关系。桃小食心虫以老熟幼虫結“越冬茧”在土內越冬,其垂直分布深度限于离土表4寸范围內,平面分布愈近树干密度愈大。越冬幼虫自6月中旬开始出土,一直延續到8月上、中旬結束,盛期在7月中旬左右。越冬幼虫出土与降雨有密切关系。在室內越冬幼虫出土及第一代老熟幼虫脫果后至成虫羽化历期,分别平均为10.4天及10.8天。成虫白天不活动,夜間11—1时之間交尾。产卵前期平均为2.5—2.7天,产卵期間平均为1.3—2.1天。雌虫平均产卵量为27.9粒(越冬代)和40.5粒(第一代),最多可产154粒。在田間,卵绝大多数产在叶片背面基部(72.6％),产在果实梗洼(27.4％)和胴部较少,其它部位尚未发现。田間卵自7月中、下旬开始发生,至8月下旬或9月初結束。第一、二代卵期分別平均为6.8和8.4天,孵化率分別为92.3％和89.5％。幼虫扎果从7月末 (或8月初) 起至9月中、下旬棗采收,前后达50天左右。幼虫脫果从8月中旬起,至9月中、下旬棗采收后尚未結束。果內幼虫期最短9天,最长28天,平均16.8天左右。地面药剂处理应該在6月中、下旬越冬幼虫出土前,这是第一个防治关鍵时期;在第一、二代卵盛期(7月下旬及8月中旬左右),噴药两次是防治桃小食心虫的第二个关鍵时期。地面药剂处理,3％666粉剂与3％666颗粒剂效果差不多。树上喷药可用25％DDT乳剂250倍液加用0.01％“拉开粉”或0.1％水胶,可以提高防治效果。     

Study on the species-specificity of Isospora michaelbakeri by experimental infection

Isospora michaelbakeri is one of the Isospora species most commonly found in the wild field, which can cause severe infection and mortality in young sparrows. In this study, we selected I. michaelbakeri (Chung Hsing strain) as a pathogen to orally inoculate russet sparrows (Passer rutilans), spotted munia (Lonchura punctulata), canary (Serinus canaria), Java sparrows (Padda oryzivora), chicken (Gallus domesticus), ducks (Anas platyrhynchos) and BALB/c mice. The results indicated that I. michaelbakeri infected only russet sparrows. Infected sparrows displayed lethargy, muscular weakness and fluffy feathers, followed by rapid death. Liver and spleen enlargement was seen in the infected birds. Schizonts were identified in thin smears from the venous blood, enlarged livers and spleens. Histopathological examination revealed schizonts and merozoites from the liver and spleen of infected russet sparrows, but not from other species experimentally inoculated with I. michaelbakeri in the present study.