不同耕作措施下旱作麦田CO2排放速率与土壤水热关系分析

采用定位试验,系统研究翻耕(T)、翻耕+秸秆还田(TS)、旋耕(RT)、旋耕+秸秆还田(RTS)、免耕(NT)、免耕+秸秆覆盖(NTS)6种不同耕作措施下土壤CO2排放速率的季节变化规律,分析土壤CO2排放速率与土壤水热的相互关系。结果表明,CO2排放速率有明显的季节变化规律,均表现为冬季低夏季高;整个生长季平均排放速率为TS>T>RTS>RT>NTS>NT,并且T、RT、NT 3种耕作措施之间差异均达到极显著水平(P<0.01);TS、RTS、NTS 3种有秸秆耕作措施的CO2排放速率均高于相应的T、RT、NT 3种无秸秆耕作措施,且T与TS之间差异达到极显著水平;土壤温度和CO2排放速率表现为极显著正相关,T、RT和NT分别与15、5、10 cm土层温度相关性最大,相关系数分别为0.899、0.779、0.934;土壤含水量与CO2排放速率未表现出显著相关性。     

A study on mechanical,thermal and environmental degradation characteristics of N,N-dimethylaniline treated jute fabric-reinforced polypropylene composites

The mechanical and thermal behavior of compression molded jute/polypropylene (PP) composites were studied by evaluating tensile strength (TS), bending strength (BS), tensile modulus (TM), bending modulus (BM), impact strength (IS), thermogravimetric (TG/DTG) and differential thermal analysis (DTA). A chemical modification was made to jute fabrics using N,N-Dimethylaniline (DMA) in order to improve the interfacial adhesion between the fabrics and matrix. It was found that jute fabrics on treatment with N,N-Dimethylaniline (DMA) significantly improved the mechanical properties of the composites. Thermal analytical data of PP, both treated and untreated jute fabrics as well as composites revealed that DMA treatment increased the thermal stability of the fabrics and composite. DMA treatment also reduced the hydrophilic nature of the composite. DMA treated jute composite was found less degradable than control composite under water, soil and simulated weathering conditions.     

Plant Therapy: a Nonpharmacological and Noninvasive Treatment Approach Medically Beneficial to the Wellbeing of Hospital Patients

A green atmosphere and interaction with nature (plants and flowers) can considerably improve the human senses and sanity by decreasing the stress associated with anxiety, depression, neurotic impairment, and other psychologic symptoms. The current paper reports a therapeutic horticultural study’s findings regarding the effect of indoor foliage plants and flower arrangements on health prospects of surgical patients. Two surgical wards, ward A (with foliage plants and arranged flowers) and ward B (without foliage plants and flowers), were selected for the study. A total of 270 patients were randomly assigned to either ward to give 135 patients in each. Patients admitted to ward A had significantly more optimistic and promising health improvements than those in ward B. Provision of foliage plants and flower arrangements to the patients in ward A resulted in shorter postoperative stays, lower intake of analgesics, lower pain intensity, less stress fatigue, and improved vital signs (blood pressure, heart rate, respiration rate, body temperature) as compared to patients in ward B. Moreover, analyses showed that patients in ward A had a stronger psychologic frame of mind regarding their recovery from surgery and had more positive emotions and feelings regarding their stay in the hospital. They also felt that the ward atmosphere was more calming, pleasant, and satisfactory. Additionally, small group discussions and focal interviews with ward doctors and nurses confirmed the findings of the questionnaire that foliage plants & flower arrangements create a cherished environment in the ward, reduce patients’ stress, improve medical and psychologic status of patients, and also conveye positive messages of the hospital. These findings confirm the therapeutic value of horticultural activities, particularly in surgical patients in a stressed hospital setting.     

Effects of shade on morphology,chlorophyll concentration,and chlorophyll fluorescence of four Pacific Northwest conifer species

Four species of Pacific Northwestconifer seedlings (ponderosa pine [Pinusponderosa Dougl. ex Laws.], Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco], westernredcedar [Thuja plicata Donn ex D. Donn], andwestern hemlock [Tsuga heterophylla (Raf.)Sarg.]) were planted in individual pots and grownunder shade-cloth shelters that provided four levelsof shade (0% [full sunlight], 35%, 55%, and 75%)for approximately 30 weeks. Height growth wasrecorded every 2 weeks. Initial and final seedlingmorphology and chlorophyll concentrations weremeasured. Chlorophyll fluorescence was measuredmonthly. All species responded similarly to shade. Although height growth was greatest under 75% shadeand least in 0% shade, total biomass production wassignificantly lower and shoot:root ratio significantlyhigher in 75% shade than in 0% shade. As thetreatment shade level increased from 0% to 75%,F_v/F_m was significantly lower whilechlorophyll concentrations were significantly higher. These results indicate that photochemical efficiencyof all four species was lower under higher shade. Morphological and physiological responses differedgreatly among species and corresponded with theirdegree of shade tolerance.     

Toxicity of Sevin (1-Naphthyl-n-Methyl-Carbamate) To Cattle Grubs, Lice, and Cattle

Sevin, a cholinergic insecticide, was used for the control of cattle lice Haemotopinus eurysternus and Bovicolar bovis and cattle grubs Hypoderma lineatum and H. bovis. Partial or complete spraying of the animal body with 0.5 per cent Sevin was equally effective for louse control and one application killed the lice and prevented reinfestation in `carrier' cows for 17-20 weeks.

The dermal or parenteral administration of Sevin to the host animal had no larvicidal effect on cattle grubs migrating in its body. Similarly, the sprays of Sevin had no lethal effect on grubs encysted in the back of cattle.

     

Endometrial nitric oxide synthase activity in mares susceptible or resistant to persistent breeding‐induced endometritis and the effect of a specific iNOS inhibitor in vitro

Emerging research suggests that the nitric oxide system may play a role in persistent breeding‐induced endometritis (PBIE) in the mare. Differences in uterine nitric oxide (NO) levels between mares susceptible or resistant to PBIE and a dose‐dependent inhibitory effect of NO on uterine contractility have been demonstrated. The objectives of this study were to investigate the difference in total nitric oxide synthase (NOS) activity of the endometrium between susceptible and resistant mares and the effect of a specific inducible nitric oxide synthase (iNOS) inhibitor on the endometrial NOS activity in vitro. Six susceptible and six resistant mares were selected based on preset criteria and the results of an intrauterine challenge with killed spermatozoa during oestrus. Endometrial biopsy samples were collected 24 hr post‐challenge and cultured at 37°C for 24 hr in L‐arginine supplemented minimum essential medium with or without a specific iNOS inhibitor (1,400 W dihydrochloride, 1 mM). The medium and the cultured endometrial tissue were collected after 24 hr of culture and assayed for NO and total protein, respectively. Total NO content of the medium, normalized to endometrial tissue wet weight or total protein, was used as a measure of endometrial NOS activity. Non‐parametric tests were applied for statistical analysis. Susceptible mares had significantly greater endometrial NOS activity than resistant mares. The iNOS inhibitor treatment significantly reduced NOS activity in endometrial samples derived from susceptible and resistant mares. These findings provide a basis for in vivo testing of specific iNOS inhibitors as preventative or therapeutic options for PBIE in mares.     

Interception of photosynthetic photon flux density in a mangrove stand of <Emphasis Type="Italic">Kandelia candel</Emphasis> (L.) Druce

The canopy structure and interception of photosynthetic photon flux density (PPFD) in a 10-year-old Kandelia candel (L.) Druce stand were investigated before and after artificial defoliation. Leaf and wood areas for different layers were measured through area–weight relationships of subsamples. PPFD was measured at specified heights before and after leaf clipping. The leaf area index (LAI) and wood area index (WAI) were 4.501m²m^–2 and 1.412m²m^–2, respectively. There was a strong linear relationship between the cumulative wood area © and leaf area (F) densities from the top down to a given depth of the canopy, C = aF (r ² = 0.950), with a proportional constant a of 0.096 ± 0.008 (mean ± SE). The PPFD relative to that above the canopy (relative PPFD; I _R) at a given depth of the canopy was assumed to be given by the equation I _R = e^–(KCC+KFF ) = e^–KF , where the apparent light extinction coefficient K (= K _F + aK _C , where K _F and K _C are respectively the light extinction coefficient of leaves and woody organs) was calculated to be 0.502 ± 0.041 (mean ± SE) m^–2m² before leaf clipping. After leaf clipping, I _RC = e^–KCC is satisfied. As a result, the value of K _C was estimated to be 0.785 ± 0.046 (mean ± SE) m^–2m². The light extinction coefficient of leaves K _F was calculated to be 0.427m^–2m² using the indirect method, K _F = K – aK _C, and 0.432 ± 0.026 (mean ± SE) m^–2m² using the direct method, I _R/I _RC = e^–KFF . Of the total PPFD intercepted by the canopy, the fraction K _F/K due to leaves alone was estimated to be 85.0%–86.1% and the rest was contributed by woody organs.     

Suspected lily-of-the-valley (Convallaria majalis) toxicosis in a dog

Objective: To describe successful treatment of third-degree atrioventricular (AV) block using temporary noninvasive transthoracic pacing and placement of a permanent transvenous pacemaker in a case of suspected lily-of-the-valley ( Convallaria majalis ) intoxication in a dog.
Case summary: A 2-year-old neutered male Beagle weighing 17.8 kg was presented to the emergency service for treatment of bradycardia, vomiting, and lethargy. An electrocardiogram revealed third-degree AV block that was nonresponsive to atropine. Ten hours after admission, the dog became obtunded. Treatment initially consisted of temporary noninvasive transthoracic pacing and eventually placement of a permanent transvenous pacemaker. The initial history did not suggest that the dog had access to any known cardiotoxins. However, C. majalis , which contains cardiac glycosides, was identified within the dog's environment and the dog's serum did contain digoxin or an immunologically cross-reactive compound.
New or unique information provided: This is the first reported successful management of C. majalis toxicosis in a dog. Temporary noninvasive transthoracic pacing was used in the management of this case as a safe and effective bridge to permanent pacemaker implantation.     

Antifungal clerodane diterpenes from Macaranga monandra (L) Muell. et Arg. (Euphorbiaceae)

Hexane and ethyl acetate phases of the methanol extract of Macaranga monandra showed fungal growth inhibition of Colletotrichum acutatum, C. fragariae and C. gloeosporioides, Fusarium oxysporum, Botrytis cinerea, Phomopsis obscurans, and P. viticola. Bioassay-guided fractionation led to the isolation of two active clerodane-type diterpenes that were elucidated by spectroscopic methods (1D-, 2D-NMR, and MS) as kolavenic acid and 2-oxo-kolavenic acid. A 96-well microbioassay revealed that kolavenic acid and 2-oxo-kolavenic acid produced moderate growth inhibition in Phomopsis viticola and Botrytis cinerea.