卷烟烟气自由基检测与清除方法研究综述

综述了卷烟烟气气相和粒相中自由基的毒性、种类、性质、检测方法及其清除剂包括天然植物类抗氧化剂、维生素、氨基酸、蛋白质、微量元素和天然矿石等,并展望了卷烟烟气自由基检测和清除的研究方向。     

佐治亚理工学院造纸科学技术研究所

佐治亚理工学院概况位于美国佐治亚州亚特兰大市的佐治亚理工学院（简称GeorgiaTech,GT）是一所公立的研究型大学,其附属分校分布于美国、法国、爱尔兰、新加坡以及中国的上海。     

Gaseous and particulate emissions from prescribed burning in Georgia

Prescribed burning is a significant source of fine particulate matter (PM2.5) in the southeastern United States. However, limited data exist on the emission characteristics from this source. Various organic and inorganic compounds both in the gas and particle phase were measured in the emissions of prescribed burnings conducted at two pine-dominated forest areas in Georgia. The measurements of volatile organic compounds (VOCs) and PM2.5 allowed the determination of emission factors for the flaming and smoldering stages of prescribed burnings. The VOC emission factors from smoldering were distinctly higher than those from flaming except for ethene, ethyne, and organic nitrate compounds. VOC emission factors show that emissions of certain aromatic compounds and terpenes such as alpha and beta-pinenes, which are important precursors for secondary organic aerosol (SOA), are much higher from active prescribed burnings than from fireplace wood and laboratory open burning studies. Levoglucosan is the major particulate organic compound (POC) emitted for all these studies, though its emission relative to total organic carbon (mg/g OC) differs significantly. Furthermore, cholesterol, an important fingerprint for meat cooking, was observed only in our in situ study indicating a significant release from the soil and soil organisms during open burning. Source apportionment of ambient primary fine particulate OC measured at two urban receptor locations 20-25 km downwind yields 74 +/- 11% during and immediately after the burns using our new in situ profile. In comparison with the previous source profile from laboratory simulations, however, this OC contribution is on average 27 +/- 5% lower.     

Staphylococcal capsular vaccine for preventing mastitis in two herds in Georgia

An encapsulated staphylococcal vaccine, consisting of heat-killed capsular-type A and B Staphylococcus aureus strains and capsular polysaccharide extracted from strain ATCC 31432 of Staphylococcus epidermidis, was used to control bovine mastitis in two herds in Georgia. The vaccine was administered intramuscularly into 97 and 125 cows in the herds, and equal numbers of animals were controls. Two weeks after primary vaccination a booster injection was given. No side effects were observed. In one herd, leucocyte content of milk samples decreased remarkably 1 wk after the booster injection. Significant resistance to infection was maintained for 4 mo after vaccination. Estimation of the total loss of milk yield showed less loss compared to that in the control group for 4 mo after vaccination. In the other herd, remarkable improvements of milk samples were observed as early as 1 wk after primary vaccination and resistance to infection continued for 6 mo after vaccination, when experiments were terminated. At 3 mo after vaccination, loss of milk yield was approximately one-third of that in the control group, and this reduction of loss was maintained for 6 mo after vaccination.     

乔治亚州烤烟种植斑萎症治理方案

1986年乔治亚州首次确认了烟草植株因番茄斑萎症病毒感染的斑萎症。自1995年开始,斑萎症所造成的损失已超过其他所有烟草病害造成损失的总和。      

Environmental effects on conception rates of Holsteins in New York and Georgia

The purpose of this study was to investigate the compounded impact on conception rates (CR) of the effects of milk production, service month, and days in milk (DIM) by using recent artificial insemination records of Holsteins in New York (NY) and Georgia (GA). Dairy Herd Improvement records were obtained from Dairy Records Management Systems in Raleigh, North Carolina. After removing records with lactations >1 and uncertain and extreme records (records without a calving or birth date, with days to service after calving of <21 or >250, and without the next calving date), the final data set comprised 298,015 service records for 160,879 cows and 23,366 service records for 12,184 cows in NY and GA, respectively, from 2000 to 2003. The analytical model included DIM class, milk-production level, service month, the covariate of cow's age at calving, and all 2-way interactions. The 2 states were analyzed separately. In general across the 2 states, CR declined as milk production increased, and CR declined during the hottest months. Conception rate was similar in NY and GA, at approximately 55% from December to April. In NY, CR declined by approximately 10% in May and June and mostly recovered by July. In GA, the CR started declining in May, bottomed at 31% in September, and did not recover until December. The difference in CR between high- and low-producing cows was 7% in NY and 6% in GA. That difference was the strongest from June to July in GA (15%) and was more uniform in NY. The increase in CR with increasing DIM varied across service season. The CR was nearly flat from 50 to 125 DIM in NY for all seasons, except for a large increasing trend in spring. In GA, there was also an increasing trend in fall. Conception rates were similar in NY and GA between December and May, and were strongly influenced by heat stress in GA from June to November. A decline in CR for reasons other than heat stress was present in both states in late spring. High production resulted in a faster decline of the CR in GA under heat stress. Models analyzing service records should include the DIM × season × region interaction.     

Historical trends in mercury sedimentation and mixing in the Strait of Georgia, Canada

Seventeen sediment cores collected in the Strait of Georgia reveal a history of mercury contamination that began in the 1860s and include episodic contamination during World War II and in the late 1960s. Surface sediment mercury concentrations ranged from 60 to 420 ng/g dry weight and the current fluxes to sediments are estimated at 5-181 ng cm(-2) a(-1). In one location in Port Moody Arm, a Hg spill seems to have sufficiently poisoned the sediments to eliminate biomixing for about 20 years. Although the surface concentration of Hg is likely to decrease at all stations in coming years, sites in the industrialized Vancouver Harbor and Port Moody Arm will continue to be sufficiently contaminated to endanger benthic organisms. Variations in sedimentation and mixing rates among sites result in surface sediment Hg concentration patterns that do not reflect accurately the distribution of Hg flux. In particular, the concentration of Hg in sediments near the mouth of the Fraser River is low, despite the high Hg load of that river, because of dilution by other particles. A preliminary Hg budget indicates that most of the Hg enters the Strait of Georgia via the Fraser River (2090 kg a(-1)), and that, while burial in Strait of Georgia sediments is a major sink (1800 kg a(-1)), there may be a significant outflow of Hg through Juan de Fuca Strait (approximately 3400 kg a(-1)).     

Estimation of primary and secondary particulate matter intake fractions for power plants in Georgia

Air pollution benefit-cost analyses depend on dispersion models to predict population exposures to pollutants, but it is difficult to determine the reasonableness of the model estimates. This is in part because validation with field measurements is not feasible for marginal concentration changes and because few models can capture the necessary spatial and temporal domains with adequate sophistication. In this study, we use the concept of an intake fraction (the fraction of a pollutant or its precursor emitted that is eventually inhaled) to provide insight about population exposures and model performance. We apply CALPUFF, a regional-scale dispersion model common in health benefits assessments, to seven power plants in northern Georgia, considering both direct emissions of fine particulate matter (PM2.5) and secondarily formed ammonium sulfate and ammonium nitrate particles over a domain within 500 km of Atlanta. We estimate emission-weighted average intake fractions of 6 x 10(-7) for primary PM2.5, 2 x 10(-7) for ammonium sulfate from SO2, and 6 x 10(-8) for ammonium nitrate from NOx, with no effect of SO2 on ammonium nitrate. To provide insight about model strengths and limitations, we compare our findings with those from a frequently applied source-receptor (S-R) matrix. Using S-R matrix over an identical domain, the corresponding intake fractions are 5 x 10(-7), 2 x 10(-7), 3 x 10(-8), and -2 x 10(-8), respectively, with the values approximately doubling if the domain is expanded to cover the continental United States. Evaluation of model assumptions and comparison of past intake fraction estimates using these two models illustrates the importance of assumptions about the relative concentrations of ammonia, sulfate, and nitrate, which significantly influences ammonium nitrate intake fractions. These findings provide a framework for improved understanding of the factors that influence population exposures to particulate matter.     

微波预处理木薯发酵酒精的研究

利用微波预处理木薯代替传统酒精发酵生产中的蒸煮液化工艺,并对微波预处理后的木薯进行无蒸煮发酵工艺的研究。通过正交试验,得出微波处理后的木薯最佳发酵条件为：料水质量比1:2.8,糖化酶添加量180U/g,活性干酵母添加量为原料质量的0.3%,氮源用量为原料质量的0.3%,30℃发酵72h,发酵醪液的酒精体积分数达到12.7%。通过与传统蒸煮液化工艺进行能耗对比,至少节省30.8% 的能耗。     

Microflora of brown shrimp (Penaeus aztecus) from Georgia coastal waters

Initial aerobic plate counts of shrimp harvested under controlled conditions were approximately 2 logs lower than counts obtained from commercially harvested shrimp and remained lower throughout 18 days of storage on ice. Commercial shrimp microflora capable of proteolysis gradually shifted to 100% by day 18. Shrimp obtained from fish markets averaged bacterial counts of 2·0 × 10⁵ on day of purchase, 45% of those were capable of proteolysis. The natural spoilage microflora of freshly caught Georgia coast shrimp were predominantly Acinetobacter, Enterobacter, and Flavobacterium species, while that of commercial shrimp was predominantly Acinetobacter, Moraxella, and Corynebacterium. After 18 days of ice storage, Acinetobacter and Flavobacterium species predominated on both fresh and commercial shrimp.     

Trends and seasonality of reproductive performance in Florida and Georgia dairy herds from 1976 to 2002

Trends in reproductive performance from 1976 to 2002 were studied for dairy farms located in Florida and Georgia using 2,897,517 Dairy Herd Improvement Association lactation records of Holstein cows. One-half of the 1552 herds in the final edited records had measures for at least 8 yr. Measures of reproductive performance changed significantly over time. Days to first service increased from a low of 84 d in 1983 to 104 d in 2001. Cows that calved during spring had 9.2 (1983) to 33.2 (1999) more days to first service than cows that calved during fall. Annual pregnancy rates (PR) for 71 to 364 d since last calving (DSC; PR_71-364) decreased from 21.6% in 1977 to 1979, to 12% in 2000 to 2002. The greatest PR_71-364 was observed during winter and the lowest during summer (15.8 vs. 5.6% in 2002, respectively). The absolute difference between PR_71-364 during winter and summer remained similar over time at 11 percentage units. Pregnancy rates in the early stages since calving (71 to 133 d) showed greater decreases over time than PR in the later stages since calving. From 1998 to 2002, PR in the later stages since calving (134 to 364 d) was on average 11.5%. Pregnancy rate from 71 to 133 DSC remained greater (13.4%). In the winter, the decrease in PR_71-364 was primarily due to a large decrease in PR_71-91. Average days to conception increased from a low of 121 in 1982 to a high of 167 in 1998. The average difference between cows that calved during spring and fall increased from 22 d in 1976 to 47.5 d in 1986, but remained constant at 39.1 d from 1985. Average calving interval increased from 399 d in 1976 to 429 d in 2000. Average days dry between 1976 and 2001 remained similar at 69 d. Days to culling of nonpregnant cows after 182 DSC increased from 341 in 1983 to 415 in 1998. Season of calving had no clear association with average days to culling. The last milk yield recorded less than 1 mo before culling of nonpregnant cows after 182 DSC decreased by DSC to approximately 1 yr since calving, after which it remained constant at an average of 12.3 kg/d. The last known milk yield of cows culled during spring was 1.6 kg/d greater than those culled during fall. This difference did not significantly change over time. Increases in actual 305-d herd milk production were associated with increased days to first service, days to conception, and calving interval, but also with increased PR_71-364. Herd size did not have a clear association with reproductive efficiency.     

Physico-chemical characteristics of juice extracted by blender and mechanical press from pomegranate cultivars grown in Georgia

Pomegranate juice is consumed widely for its possible health benefits. The aril juice from 15 pomegranate cultivars grown in Georgia were analysed for juice yield based on fresh weight (FW) and physico-chemical properties, using blender and mechanical press extraction. Blender had a higher juice yield (42.04% FW) compared to mechanical press (38.05% FW). Total phenolics and antioxidant capacity was determined by Folin–Ciocalteau method and ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays, respectively. Total monomeric anthocyanins were determined by pH differential method and RP-HPLC. The major anthocyanin was delphinidin 3-glucoside. High negative and significant (p ? 0.05) correlations were found between pH and titratable acidity (TA). The total soluble solids content (TSS) averaged 15.59 in blender and 14.94 °Brix in mechanical press. Chemical analysis of juice showed significant differences among cultivars and extraction methods. Overall, blender was more efficient than mechanical press juice extraction.     

Pregnancy rates and milk production in natural service and artificially inseminated dairy herds in Florida and Georgia

Effects of artificial insemination (AI) and natural service (NS) breeding systems on pregnancy rates (PR) by stage of lactation, season, and changes in milk production over time were examined using lactation and herd DHIA records of Holstein cows in dairy herds located in Florida and Georgia. The reported genetic profile of service sires of the herd was used to determine the percentage of cows bred to natural service bulls (%NS). Two seasons were considered: winter (November-April) and summer (May-October) from 1995 to 2002 (16 periods). Herd-periods were assigned 1 of 3 breeding systems: AI (0 to 10% NS), mixed (11 to 89% NS) and NS (90 to 100% NS). Seventy percent of the herds used NS bulls as a component of their breeding system during the study period. The PR during winter (17.9%) was greater than that during summer (9.0%). During winter, PR for AI herds (17.9%) did not differ from that for mixed (17.8%) and NS herds (18.0%). During summer, PR for AI herds (8.1%) was slightly less than that for mixed (9.3%) and NS herds (9.8%). During winter, PR for cows at 71 to 91 d, 92 to 112 d, and 113 to 133 d in milk were 1.4% lower for mixed herds compared with AI and NS. Pregnancy rate for NS herds was 2.6% lower during late lactation compared with AI and mixed herds. During summer, PR for cows at 71 to 91 and 92 to 112 d in milk were 2.6 and 1.8% greater, respectively, for NS herds compared with AI. However, from 260 to 364 d in milk, PR for NS herds was less than that for AI and mixed herds. No significant interaction was detected between breeding system and lactation number. Rolling herd average milk production during the study period was less in the NS herds (7180 kg) compared with AI (8513 kg) and mixed herds (8176 kg), but the annual change in milk production was not different among breeding systems. The results indicated that use of NS bulls did not result in meaningful disadvantages in terms of PR and changes in milk production over time.     

Actual nutrition and health of several groups of rural and urban population of the Republic of Georgia]

The results of the study have shown that the nutrition of rural population is characterized by excessive consumption of bread and baked products, by high content of phosphorus, magnesium and iron, low content of animal proteins, vegetable oils, calcium, vitamins A, ascorbic acid and riboflavin. The incidence of cardiovascular, respiratory and alimentary diseases in this group of population was rather high. The nutrition of students is characterized by excessive consumption of polysaccharides, vegetable oils, thiamine, niacin, ascorbic acid (in winter-spring period), and calcium. Diseases associated with nutrition disorders (obesity, hepatitis, cholecystitis, colitis) are most often recorded in this group of population.     

Effect of in ovo exposure to PCBs and Hg on Clapper Rail bone mineral chemistry from a contaminated salt marsh in coastal Georgia

The effect of Hg and PCBs (Aroclor 1268) on bone characteristics was investigated in a population of Clapper Rails (Rallus longirostris) inhabiting contaminated and unimpacted estuarine marsh systems in coastal Georgia. Exposure to contaminants did not affect the length or weight of leg bones, but it significantly altered the chemical composition of the bone. Specifically, bone in the contaminated site had a higher Ca to P, and lower carbonate and acid phosphate content. These characteristics are typical of more mature bone mineral and indicate that toxicants have accelerated bone maturation. FTIR spectroscopy data revealed a dose dependent change in the crystallinity of bone mineral, and the relative proportion of specific PO4 groups in different molecular environments in the bone, with toxicants loads. These changes are most probably related to a hormonal alteration of the rate of bone remodelation induced by exposure to toxicant loads.