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1.
Leonard P Gianessi 《Pest management science》2013,69(10):1099-1105
Herbicide use is increasingly being adopted around the world. Many developing countries (India, China, Bangladesh) are facing shortages of workers to hand weed fields as millions of people move from rural to urban areas. In these countries, herbicides are far cheaper and more readily available than labor for hand weeding. History shows that in industrializing countries in the past, including the United States, Germany, Japan and South Korea, the same phenomenon has occurred—as workers have left agriculture, herbicides have been adopted. It is inevitable that herbicide use will increase in sub‐Saharan Africa, not only because millions of people are leaving rural areas, creating shortages of hand weeders, but also because of the need to increase crop yields. Hand weeding has never been a very efficient method of weed control—often performed too late and not frequently enough. Uncontrolled weeds have been a major cause of low crop yields in sub‐Saharan Africa for a long time. In many parts of the world, herbicides are being increasingly used to replace tillage in order to improve environmental conditions. In comparison with tillage, herbicide use reduces erosion, fuel use, greenhouse gas emissions and nutrient run‐off and conserves water. © 2013 Society of Chemical Industry 相似文献
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以发生于本市的一起兔病毒性出血症与大肠杆菌病混合感染的病例为题材,从发病情况、临床症状、病变、实验室检查、防治等几个方面作了详尽的阐述,为临床上治疗该病提供参考依据。 相似文献
3.
A tunable kondo effect in quantum dots 总被引:1,自引:0,他引:1
A tunable Kondo effect has been realized in small quantum dots. A dot can be switched from a Kondo system to a non-Kondo system as the number of electrons on the dot is changed from odd to even. The Kondo temperature can be tuned by means of a gate voltage as a single-particle energy state nears the Fermi energy. Measurements of the temperature and magnetic field dependence of a Coulomb-blockaded dot show good agreement with predictions of both equilibrium and nonequilibrium Kondo effects. 相似文献
4.
M Asakawa JW Ludders B Badgley HN Erb LP Posner RD Gleed 《Veterinary anaesthesia and analgesia》2005,32(4):12-13
Adenosine is a potent analgesic in people and reduces the MAC of halothane in dogs. The purpose of this study was to determine whether adenosine reduces the MAC of isoflurane in dogs. Seven beagles (four males and three females) were anesthetized and randomly assigned to receive adenosine (0.3 mg kg–1 minute–1; 6 mL kg–1 hour–1, IV) or saline (0.9%, 6 mL kg–1 hour–1IV). After an interval of ≥7 days, each dog was reanesthetized and treated with the alternate infusion. Anesthesia was induced and maintained with isoflurane in oxygen. Dogs were intubated and instrumented for measurement of mean systemic arterial blood pressure and airway concentration of isoflurane and end‐tidal partial pressure of carbon dioxide. The MAC for isoflurane was determined using the tail‐clamp technique. Baseline MAC values were 1.25 (1.15, 1.35)% [median (minimum, maximum)] and 1.25 (1.05, 1.45)% before the saline and adenosine treatments, respectively. After 2 hours of infusion with saline or adenosine, MAC values were not different (p = 0.156) and were 1.25 (0.95, 1.35)% and 1.05 (1.00, 1.25)%, respectively. Two hours following the end of each infusion, the MAC values for saline and adenosine treatment groups differed significantly (p = 0.015), but by no more than the normal variation inherent in this study, and were 1.15 (1.15, 1.35)% and 1.05 (1.05, 1.25)%, respectively. Mean arterial blood pressure was 93 (74, 123) mm Hg for saline treated dogs and 67 (52, 72) mm Hg (p = 0.008) during adenosine infusion. End‐tidal carbon dioxide was not different between the two treatment groups. We conclude that adenosine administered at 0.3 mg kg–1 minute–1had no effect on isoflurane MAC in dogs, but decreased mean arterial blood pressure. 相似文献
5.
Aftertaste is a taste perceiption after a food or beverage is either swallowed or spat out.The primary taste processing area located in the insula was considered to be involved in aftertaste perception.The changes in chemical compositions lead to the changes in aftertaste of tea.Tea fermentation,in which tea catechins are transformed into thearubigins,lead to a strong,distinctive flavor but a plain aftertaste.Theanine has a sweet taste,with little or no aftertaste.The bitter aftertaste of transglucosylated steviosides was reduced when they were converted through transglucosylation of stevioside by α-amylase.Characteristics of aftertaste include quality,intensity,and duration.Foods that have lingering aftertastes typically have long sensation durations.A surface plasmon resonance (SPR) system immobilized β-cyclodextrin indicated larger responses for the gallate-type catechins in comparison to the non-gallate-type catechins.The β-cyclodextrin/SPR system can sense the bitter-astringent taste intensity of the green tea.The SPR system detected the stability of the complex between the gallate-type catechins and β-cyclodextrin,which can be interpreted as the aftertaste produced in humans by the gallate-type catechins. 相似文献
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7.
H Chevalier LP Posner JW Ludders HN Erb RD Gleed 《Veterinary anaesthesia and analgesia》2003,30(2):114-114
Our purpose was to assess the accuracy and precision of a point of care hemoglobinometer (HemoCue‐B hemoglobin photometer) for measuring hemoglobin concentration in horse blood. Samples of jugular venous blood from 12 healthy adult horses were collected in EDTA. In order to test the device over a wide range of values, each sample was divided into nine aliquots, and autologous plasma was added or removed from the aliquots to produce blood with PCV values that approximated 5, 10, 20, 30, 40, 50, 60, 70, and 80%, respectively. The aliquots were rocked to ensure mixing of plasma and cells. Then hemoglobin by HemoCue‐B (HbHQ) and hemoglobin by the cyanmethemoglobin method (HbCY) were measured on each aliquot. The PCV of each aliquot was also measured and this value was used for subsequent analyses. To test repeatability, hemoglobin was measured twice by the HemoCue‐B on approximately 40% samples. Samples with HbHQ >25.4 g dL?1 required dilution prior to analysis. HbCY ranged from 1.6 to 33.4 g dL?1. After regression, HbCY = ?0.16 + 1.04 HbHQ (n = 101; r2 = 99.6%). By inspection of a modified Bland‐Altman plot, HbHQ values <16 g dL?1 closely approximated HbCY; however, at greater values, HbHQ underestimated HbCY by as much as 3.2 g dL?1. The difference between repeated measurements with the HemoCue‐B was 0.02 ± 0.16 g dL?1 (mean ± SD; n = 10) and nonsignificant. After regression, PCV = ?0.76 + 2.78 HbHQ (n = 101; r2 = 99.4%). We conclude that HemoCue‐B can be used to measure hemoglobin concentration in horse blood, and that it is accurate when hemoglobin is <16 g dL?1. PCV can be estimated by multiplying HbHQ by 2.8 and then subtracting 0.8. 相似文献
8.
AIMS: To retrospectively evaluate the medical and surgical records of horses with acute small intestinal obstructions associated with Parascaris equorum infection; to describe the gastrointestinal lesions; and to determine the outcome of cases with such lesions. METHODS: Records of 25 horses with acute small intestinal obstruction associated with P. equorum between 1985 and 2004 were reviewed to determine signalment, history, physical examination, surgical or post-mortem findings, and outcome. RESULTS: All horses except one were less than 12 months old. Standardbreds were over-represented in the population studied. Sixteen horses (72%) had been administered anthelmintics, including pyrantel (n=8), ivermectin (n=7), and trichlorphon (n=1), within 24 h prior to the onset of colic. Of the 25 cases reviewed, 16 had simple obstructive ascarid impactions (SOAIs), and nine had complicated obstructive ascarid impaction (COAI) including volvulus (n=6) or intussusception (n=3), both concurrent with ascarid impaction of the small intestine. Short-term survival (discharge from hospital) occurred in 79% of horses treated for SOAI, and was 64% for all horses. Long-term survival (>1 year) occurred in 33% of horses with SOAI, and the overall long-term survival was 27% for all horses. Formation of adhesions was the most frequent finding associated with death for horses that did not survive long-term. CONCLUSIONS AND CLINICAL RELEVANCE: The incidence of anthelmintic treatment within 24 h of the onset of colic in this study population (72%) was higher than that previously reported. Resistance of P. equorum to ivermectin recently reported in Ontario may be associated with increased ascarid burdens, predisposing horses to ascarid impaction. The long-term survival of these horses was better than that reported previously. 相似文献
9.
Economic impacts of glyphosate-resistant crops 总被引:2,自引:0,他引:2
Gianessi LP 《Pest management science》2008,64(4):346-352
Glyphosate-resistant crops have been widely planted since their introduction in 1996. Growers have numerous choices for herbicide treatments and have chosen to plant glyphosate-resistant crops on the basis of economic factors. The economic effects of the widespread planting of glyphosate-resistant crops have included reductions in herbicide expenses, increases in seed costs, increased yield and changes in the relative profitability of crops that has resulted in changes in which crops are planted. In addition, non-pecuniary benefits have accrued as a result of the simplicity of weed management in the glyphosate-resistant crop systems. 相似文献
10.
Colostrum yield and litter performance in multiparous sows subjected to farrowing induction
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MA Otto AP Machado LP Moreira ML Bernardi ML Coutinho IS Vaz Jr I Wentz FP Bortolozzo 《Reproduction in domestic animals》2017,52(5):749-755
The consumption of colostrum at a low level can compromise the survival and growth of piglets. Therefore, this study aimed to evaluate the effect of farrowing induction on colostrum yield, IgG concentration and the survival and performance of piglets until the weaning. Sows of parity 3 to 7 were assigned into two groups: Control (n = 48), sows with spontaneous farrowing; and induction (n = 48), sows induced to farrow on day 114 of gestation with a PGF2 analogue. Colostrum and blood samples were collected from the sows, at farrowing and 24 hr later. Blood samples from the piglets were collected at 24 hr after birth. The performance of the piglets was evaluated in a subsample of 28 litters from each group. All piglets were weighed at 7, 14 and 20 days of age. The farrowing length, the number of piglets born alive, stillborn piglets, weight at birth, litter weight at birth and colostrum yield were not significantly affected (p > .05) by farrowing induction. There was no difference between the groups (p > .05) in the percentage of sows with obstetric interventions. Serum IgG concentration, in both sows and piglets, and colostrum IgG concentration were similar between the groups (p > .05). Furthermore, survival rate, piglet weight and litter weight at 7, 14 and 20 days of age were also similar between the groups (p > .05). Therefore, it can be concluded that the farrowing induction performed on day 114 of gestation does not affect the colostrum yield, the IgG concentration in colostrum and serum of piglets, and the litter performance until the weaning. 相似文献