Effects of salinity on osmoregulation,growth and survival in Asian swamp eel (Monopterus albus) (Zuiew 1793)

The Asian swamp eel Monopterus albus is normally considered a freshwater species, but can also occasionally be found in brackish water. It is an obligate air‐breather with highly reduced gills, making its osmoregulation physiology interesting because the gills normally represent the primary site of osmoregulation in teleosts. Being a popular fish for human consumption, the swamp eel is cultured extensively in freshwater ponds in the Mekong Delta of Vietnam. However, very little is known about its salinity tolerance, which is becoming topical due to the increasing salt‐water intrusions into tropical deltas. We therefore studied how increased salinity affects survival, growth, blood pressure, heart rate, blood osmolality and plasma ions. All eels survived prolonged exposure to 5 and 10 g L^?1, although plasma osmolality increased significantly at 10 g L^?1. Further elevation to 15 and 20 g L^?1 was associated with significantly elevated mortality, with a corresponding increase in plasma osmolality and ion con‐centrations. Our results show that swamp eels thrive in 0–10 g L^?1 with an optimum growth between 0 and 9 g L^?1, indicating that utilization of low saline brackish waters for aquaculture is possible.     

An evaluation of fresh gas flow rates for spontaneously breathing cats and small dogs on the Humphrey ADE semi‐closed breathing system

ObjectiveTo evaluate the fresh gas flow (FGF) rate requirements for the Humphrey ADE semi-closed breathing system in the Mapleson A mode; to determine the FGF at which rebreathing occurs, and compare the efficiency of this system to the Bain (Mapleson D) system in spontaneously breathing cats and small dogs.Study DesignProspective clinical study.AnimalsTwenty-five healthy (ASA score I or II) client-owned cats and dogs (mean ± SD age 4.7 ± 5.0 years, and body weight 5.64 ± 3.26 kg) undergoing elective surgery or minor procedures.MethodsAnaesthesia was maintained with isoflurane delivered via the Humphrey ADE system in the A mode using an oxygen FGF of 100 mL kg⁻¹ minute⁻¹. The FGF was then reduced incrementally by 5–10 mL kg⁻¹minute⁻¹ at approximately five-minute intervals, until rebreathing (inspired CO₂ >5 mmHg (0.7 kPa)) was observed, after which flow rates were increased. In six animals, once the minimum FGF at which rebreathing occurred was found, the breathing system was changed to the Bain, and the effects of this FGF delivery examined, before FGF was increased.ResultsRebreathing did not occur at the FGF recommended by the manufacturer for the ADE. The mean ± SD FGF that resulted in rebreathing was 60 ± 20 mL kg⁻¹minute⁻¹. The mean minimum FGF at which rebreathing did not occur with the ADE was 87 ± 39 mL kg⁻¹minute⁻¹. This FGF resulted in significant rebreathing (inspired CO₂ 8.8 ± 2.6 mmHg (1.2 ± 0.3 kPa)) on the Bain system.ConclusionsThe FGF rates recommended for the Humphrey ADE are adequate to prevent rebreathing in spontaneously breathing cats and dogs <15 kg.Clinical relevanceThe Humphrey ADE system used in the A mode is a more efficient alternative to the Bain system, for maintenance of gaseous anaesthesia in spontaneously breathing cats and small dogs.     

Application of Airway Pressure Therapy in Veterinary Critical Care: Part I: Respiratory Mechanics and Hypoxemia

Over the past several decades, recognition of acute respiratory failure as the cause of death in patients suffering from various clinical conditions has prompted aggressiv investigation into the area of respiratory physiology and supportive respiratory care. With the evolution of emergency medicine and critical care services in both human and veterinary medicine, many patients previously considered unsalvageable due to the severity of their underlying disease are now being resuscitated and successfully supported, creating a new population of critically ill patients. Where only a decade ago these patients would have succumbed to their underlying disease, they now survive long enough to manifest the complications of shock and tissue injury in the form of acute respiratory failure. Investigation into the pathophysiology and treatment of this acute respiratory distress syndrom (ARDS) has facilitated increased clinical application of respiratory theerapy and machanical ventilation.¹ The purpose of this paper is to provide a basic review of respiratory mechanics and the pathophysiology of hypoxemia as they relate to airway pressure therapy in veterinary patients and to review the use of airway pressure therapy in veterinary patients This paper is divided into two parts; part I reviews respiratory mechanics and hypoxemia as they apply to respiratory therapy, while part II deals specifically with airway pressure therapy andits use in clinical cases.     

水稻赤枯病防治技术研究

2005年,环渤海地区较大面积发生水稻红苗病.对发病田的大量现场调查发现,大多数田块的发病症状属于根中毒型赤枯病,少数田块属于缺锌、缺钾型赤枯病,个别田块是由于稻水象甲危害造成.诱发赤枯病的因素很多,但主要是低温缺氧造成的.其防治措施主要有改进耕作技术、改革水层管理和科学施肥等.     

油罐呼吸系统的检查与维护

油罐呼吸系统是保障油罐安全运行和减少油料蒸发损耗的的安全系统，定期对呼吸系统进行检查维护是保护保证油罐正常工作的重要措施，分析介绍了地面立式油罐和半地下立式油罐呼吸系统，洞式油罐呼吸系统，卧式油罐呼吸系统，粘油罐呼吸系统的组成，阐述了油罐呼吸系统的机械呼吸阀，液压安全阀，阻火器的检查维护及洞式油罐，粘油罐呼吸系统的检查维护。     

Plethysmographic comparison of breathing pattern in heaves (recurrent airway obstruction) versus experimental bronchoconstriction or hyperpnea in horses

BACKGROUND: Horses with recurrent airway obstruction (heaves) are described as exhibiting "increased abdominal effort," but it is unknown whether this translates to an effective contribution to ventilation. HYPOTHESIS: We hypothesized that heaves is characterized by asynchrony between rib cage and abdominal motions, and that the abdominal component is the major contributor to ventilation. ANIMALS: The rib cage versus abdominal motion in naturally occurring heaves (n = 15) was compared to controls at rest (n = 7) and during hyperpnea because of lobeline treatment, and the effects of histamine-induced bronchoconstriction in controls (n = 10). METHODS: Flow patterns, phase angle (theta) between the rib and abdominal compartments, abdominal (Vabd) contribution to tidal volume (VT), and lung mechanics were measured. RESULTS: Findings unique to the heaves group included the loss of biphasic expiratory flow, severely increased theta with the abdomen consistently lagging behind the rib cage, and a reduced contribution of the abdomen to ventilation. A subgroup of heaves (n = 5) with abdominal paradox showed a significant (P < .05) reduction in tidal volume, and increased respiratory rate. Bronchodilation reduced theta in heaves (P = .06), but theta remained significantly higher after bronchodilation than found in controls. CONCLUSIONS AND CLINICAL IMPORTANCE: We conclude that breathing pattern in horses with heaves is characterized by severe rib cage/abdominal asynchrony, with the rib cage motion in synchrony with flow, therefore dominating ventilation. In a subset of heaves, the abdominal compartment (diaphragm, abdominal muscles) was completely out of synchrony with flow ("abdominal paradox") despite the clinical appearance of "increased abdominal effort."     

紫锥菊根末的安全药理学研究

对健康昆明小鼠连续一周灌服不同浓度的紫锥菊根末生药液,观察其对健康昆明小鼠中枢神经系统、呼吸系统和心率的影响,以考察紫锥菊根末的潜在不良反应.结果表明,紫锥菊根末对健康昆明小鼠的中枢神经系统、呼吸系统和心率均无明显影响.     

不连续气体交换循环呼吸模式下西藏飞蝗和东亚飞蝗的呼吸特征参数

为解析西藏飞蝗对青藏高原干燥低氧环境的呼吸适应机制,本研究比较不连续气体交换循环(discontinuous gas exchange,DGC)呼吸模式下西藏飞蝗Locusta migratoria tibetensis与东亚飞蝗L.m.manilensis的呼吸特征参数。结果表明:西藏飞蝗和东亚飞蝗4、5龄蝗蝻及雄成虫均采用DGC呼吸模式,且雄成虫呼吸速率的峰值和周期比其4、5龄蝗蝻更稳定;西藏飞蝗4龄蝗蝻DGC历时为13.75 min,显著高于东亚飞蝗的6.46 min,而其5龄蝗蝻和雄成虫DGC历时分别为7.46 min和8.53 min,显著低于东亚飞蝗的15.70 min和14.44 min;西藏飞蝗4、5龄蝗蝻的暴发间期历时所占比例分别为7.40%和26.70%,显著低于东亚飞蝗4、5龄蝗蝻(分别为22.20%和67.20%),其雄成虫暴发间期历时所占比例为79.20%,显著高于东亚飞蝗雄成虫的53.60%;西藏飞蝗4、5龄蝗蝻和雄成虫代谢率分别为3.92、3.81和2.90 W/kg,与东亚飞蝗4、5龄蝗蝻和雄成虫差异不显著(分别为4.27、3.45和3.07 W/kg)。西藏飞蝗分布于低氧高海拔青藏高原,其DGC历时和暴发间期历时所占比例异于东亚飞蝗,表明DGC呼吸模式与其对高原环境的适应有关。     

Effects of algae particle size on the breathing and feeding of filter‐feeding silver carp (Hypophthalmichthys molitrix Val.)

A variety of parameters associated with breathing and feeding of silver carp were measured in response to declines in dissolved oxygen (DO) levels when the fish were fed microalgae Padorina morum (PM group) and Chlorella ellipsoidea (CE group), respectively, to explore the relationship between breathing and feeding while filtering microalgae particles at different DO levels. The results indicated that (i) respiratory frequency (f_R) of the fish in CE group were higher significantly than those in PM group at DO levels of 0.98–7.49 mg/L (P < 0.05); respiratory stroke volume (V_S.R), gill ventilation (V_G) and V_G/VO₂ the fish in two groups began to increase sharply while DO levels declined to below 4.04 mg/L (P < 0.05); oxygen extraction efficiency (EO₂) of the fish in two groups increased significantly with decline of DO levels from 7.49 mg/L to 0.98 mg/L (P < 0.05); (ii) the infiltration rate (FR) and filtering efficiency (E) of the fish in two groups began to decrease significantly while DO levels declined to below 4.04 mg/L (P < 0.05); clearance rate (CR) of fish in PM group was sixfold higher than that in CE group at DO levels of 0.98–7.49 mg/L (P < 0.05). In addition, antifiltering response appeared at DO levels of 2.21 mg/L and 0.98 mg/L in both groups. This study indicated that ‘filtration effect’ is dominant when the fish filter algae particles larger than its gill raker gaps, while the ‘food sinking effect’ is dominant when the fish filter algae particles smaller than its gill raker gaps.     

大豆叶片主要生理作用间的相关性研究

利用Minicuvette-CO_2和H_2O分析系统对大豆全生育期间植株叶片主要生理作用变化进行了活体、同步跟踪测定及25个品种间的同步比较测定,并用数理分析方法剖析了叶片光合、蒸腾、呼吸及叶导性间的相关性。结果表明,除单叶生长期光合与呼吸间呈极显著线性负相关外,光合、蒸腾、叶导性及呼吸间,无论在单叶全生长、衰老过程中或植株全生育过程中,均呈显著或极显著线性正相关;除单叶旺盛功能期光合与叶导性间的偏相关系数不显著外,光合、蒸腾和叶导性间,以及光合与呼吸间还存在着显著或极显著二级偏正相关;这类生理作用间所表现出的相关性是具有遗传基础的。