水资源不均等分配及其影响分析以簸箕李灌区为例

以簸箕李灌区为例,分析了该灌区水资源不均等分配及其所带来的对水资源利用方式和效率的影响。结果表明,在灌区内部从上游到下游,水资源可利用量很不均等,上游享用更多的水资源,地下水起到了调节水资源可用量年内波动的作用。上游地区地下水调节了春季水资源可用量的变异性,下游汛期储存的地下水在来年春季被重新利用,年平均利用量达到降雨灌溉总量的40.7%。下游农民应对水资源短缺的另2种途径是进行排水管理和减少种植面积,平均排水再利用量达到40 mm,因此下游地区具有更高的水资源利用效率。在水资源配置中应注意配置方案对水资源利用方式和效率的影响,同时要兼顾效率和公平。     

Changes in the content of bioactive polyphenolic compounds of olive mill wastewater by the action of exogenous enzymes

The aim behind the present research is to develop an enzymatic treatment for olive mill wastewater (OMW) to release high amounts of simple phenolics having high antioxidant value. OMW was hydrolyzed by a mixed enzyme preparation rich in β-glucosidase produced by Aspergillus niger . This research shows that A. niger β-glucosidase played a major role in the release of simple phenolic compounds from OMW. These compounds were recovered by ethyl acetate extraction and identified by HPLC and LC-MS. The main identified phenolic compound is hydroxytyrosol. The results of enzymatic hydrolysis of OMW under optimum conditions indicated a maximum hydroxytyrosol concentration of 2.9 g L(-1) compared to 0.015 g L(-1) contained in the control (test without added enzyme). The above results prove that OMW is a potential substrate for producing hydroxytyrosol through enzymatic hydrolysis of its glycosides.     

Photon-induced Kondo satellites in a single-electron transistor

We measure the differential conductance of a single-electron transistor (SET) irradiated with microwaves. The spin-entangled many-electron Kondo state produces a zero-bias peak in the dc differential conductance if the quantum dot in the SET contains an unpaired electron. When the photon energy hf is comparable to the energy width of the Kondo peak and to e (the charge on the electron) times the microwave voltage across the dot, satellites appear in the differential conductance shifted in voltage by +/-hf/e from the zero-bias resonance. We also observe an overall suppression of the Kondo features with increasing microwave voltage.     

Egg hatching rate and fatty acid composition of Acartia bilobata (Calanoida,Copepoda) across cold storage durations

To investigate egg storage capacity of the copepod Acartia bilobata for aquaculture interest, we tested hatching success rate (HSR) of inclusive eggs (mixture of all egg types) after 4°C storage. The HSR peaked after 14 days storage when incubating at 28°C for 48 hr (85.8 ± 1.6%) and 72 hr (87.6 ± 0.9%), then gradually declined until 1 year (48 hr: 7 ± 0.6%; 72 hr: 19.4 ± 3.9%). Reallocation of fatty acid profile suggests that docosahexaenoic acid (DHA) is correlated with the HSR of A. bilobata eggs. Additionally, we investigated the HSR of diapausing eggs (unhatched eggs after 72 hr incubation of the inclusive eggs) after 4°C storage. Their HSR peaked after 14 days storage (48 hr:75.3 ± 3.5%; 72 hr:78.2 ± 2.1%), then gradually declined until 60 days (48 hr HSR:42.1 ± 2.3%; 72 hr HSR:53.0 ± 3.2%). Overall, we illustrated the hatchability of diapausing and quiescent eggs of A. bilobata after 4°C storage. The cold storage capacities were low (<60% HSR after 60 days), and it could be limited by the egg DHA content. Our findings provide implications for future studies aiming to improve cold storage techniques of tropical copepod eggs for aquaculture applications.     

The Nutrient Expert decision support system improves nutrient use efficiency and environmental performance of radish in North China

Excessive fertilization has led to nutrient use inefficiency and serious environmental consequences for radish cultivation in North China.  The Nutrient Expert (NE) system is a science-based, site-specific fertilization decision support system, but the updated NE system for radish has rarely been evaluated.  This study aims to validate the feasibility of NE for radish fertilization management from agronomic, economic, and environmental perspectives.  A total of 46 field experiments were conducted over four seasons from April 2018 to November 2019 across the major radish growing regions in North China.  The results indicated that NE significantly reduced N, P₂O₅, and K₂O application rates by 98, 110, and 47 kg ha⁻¹ relative to those in the farmers’ practice (FP), respectively, and reduced N and P₂O₅ inputs by 48 and 44 kg ha⁻¹, respectively, while maintaining the same K₂O rate as soil testing (ST).  Relative to FP and ST, NE significantly increased radish yield by 2.7 and 2.6 t ha⁻¹ (4.2 and 4.0%) and net returns by 837 and 432 USD ha⁻¹, respectively.  On average, NE significantly improved the agronomic efficiency (AE) of N, P, and K (relative to FP and ST) by 42.4 and 31.0, 67.4 kg kg⁻¹ and 50.9, and 20.3 and 12.3 kg kg⁻¹; enhanced the recovery efficiency (RE) of N, P, and K by 11.4 and 7.0, 14.1 and 7.5, and 11.3 and 6.3 percentage points; and increased the partial factor productivity (PFP) of N, P, and K by 162.9 and 96.8, 488.0 and 327.3, and 86.9 and 22.4 kg kg⁻¹, respectively.  Furthermore, NE substantially reduced N and P₂O₅ surpluses by 105.1 and 115.1 kg ha⁻¹, respectively, and decreased apparent N loss by 110.8 kg ha⁻¹ compared to FP.  These results indicated that the NE system is an effective and feasible approach for improving NUE and promoting cleaner radish production in North China.     

Response of cotton genotypes to water and heat stress: from field to genes

Cotton is a crop of tropical and subtropical regions but the seed cotton yield is highly influenced by abiotic stresses like drought and heat. Response of cotton genome to abiotic stresses is highly complex and involve many genes. A comprehensive study, involving cotton genotypes developed through conventional and synthetic tetraploid method, was designed to (i) study the introgression of heat and water stress tolerance by using wild relatives (ii) evaluate genetic markers for marker assisted selection against water and heat stress. Two separate experiments for water and heat stress tolerance with a common control were established. Treatments in each experiment include a control and a stress treatment. Heat stress was applied by sowing crop two month earlier than the control treatment, whereas water stress was imposed by withholding alternate irrigation. Analyses of variance depicted highly significant (P ≤ 0.01) effect of genotypes and both stresses on boll retention, boll weight and seed cotton yield. Interaction of genotypes with stress in both experiments was also highly significant (P ≤ 0.01). Genotypes derived from interspecific crosses performed consistently in stress conditions compared to control which prove it a reliable method to introgress stress related genes from wild parents. Four genes reported for water stress tolerance and five genes reported for heat stress tolerance were evaluated by field results for efficient marker assisted selection (MAS). Results verified drought stress genes but heat stress genes could not explain genetic variability caused by heat stress. It is concluded from the results that separate genes may be responsible for heat stress tolerance for vegetative and reproductive stages, therefore, selection criteria should include both the traits.     

Synergetic use of biochar and synthetic nitrogen and phosphorus fertilizers to improves maize productivity and nutrient retention in loamy soil

Abstract

This study was designed to investigate the effect of biochar on maize production and nutrient retention with recommended full and half dose of nitrogen (N) and phosphorus (P) nutrition in loamy soil. In the first study, maize was grown in pots with four levels of biochar (0, 2, 4, and 6?t?ha^?1) under two levels of NP fertilizer, viz. recommended (200–150?kg?NP?ha^?1) and it’s half (100–75?kg?NP?ha^?1) dose. The prominent improvement in plant roots traits, leaf area, plant growth, morphological and yield-related parameters were observed with addition of biochar at 2 and 4?t?ha^?1; while, plant height, number of grains per cob, grains and biological yield decreased with biochar addition 6?t?ha^?1 along with full dose of NP nutrition. In subsequent field studies, two levels of biochar along with control (0, 2, 4?t?ha^?1) were investigated. The more improvement in root growth, leaf area and crop growth was observed when biochar was applied at 2?t?ha^?1 with full NP nutrition. Biochar application at 2?t?ha^?1 with full NP nutrition produced the highest grain yield (6.64?t?ha^?1); however, biochar addition (2?t?ha^?1) with half NP nutrition resulted in better grain yield than full dose of NP to enhance maize production as compared with full dose of NP without biochar. Therefore, biochar addition (2?t?ha^?1) with half-recommended dose of NP prominently improved the maize productivity in loamy soil and serve as better in replacement of full dose of NP fertilizer.     

Efficacy and toxicity of carboplatin in the treatment of macroscopic mesenchymal neoplasia in dogs

Palliative chemotherapy options for dogs with macroscopic non-osseous mesenchymal tumours are limited. The purpose of this study was to assess the response rate of these tumours to carboplatin chemotherapy. Medical records of 28 dogs treated with carboplatin for macroscopic mesenchymal neoplasia between 1990 and 2022 were retrospectively reviewed. Sixteen dogs with soft tissue sarcoma and 12 dogs with haemangiosarcoma were included. Responses observed included one complete response and three partial responses, for an overall response rate of 14.2% (4/28) and median time to progression of 42 days (range 21–259 days). Responses were only seen in patients with haemangiosarcoma, for a response rate of 33.3% (4/12) and median time to progression for responders of 103 days (range 39–252 days). Median time to progression for dogs with metastatic disease was similar to those with only local disease (distant median: 44 days; local median: 23 days, p = 0.56). Dogs with chemotherapy-naïve disease were compared to dogs having received previous chemotherapy treatment and had a median time to progression of 75 days and 40.5 days respectively (p = 0.13). Twenty-two dogs experienced 48 adverse events, with most being grade 1 or 2 (79%). Carboplatin was well tolerated, with variable macroscopic anti-tumour activity and short response duration. Carboplatin may be an acceptable rescue option for dogs with macroscopic haemangiosarcoma, especially those patients that cannot receive doxorubicin.