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."     

Clinical effect of buprenorphine or butorphanol,in combination with detomidine and diazepam,on sedation and postoperative pain after cheek tooth extraction in horses

The objective of this study was to compare effects of butorphanol (BUT) or buprenorphine (BUP), in combination with detomidine and diazepam, on the sedation quality, surgical conditions, and postoperative pain control after cheek tooth extraction in horses, randomly allocated to 2 treatment groups (BUT: n = 20; BUP: n = 20). A bolus of detomidine (15 μg/kg, IV) was followed by either BUP (7.5 μg/kg, IV) or BUT (0.05 mg/kg, IV). After 20 min, diazepam (0.01 mg/kg, IV) was administered and sedation was maintained with a detomidine IV infusion (20 μg/kg/h), with rate adjusted based on scores to 5 variables. All horses received a nerve block (maxillary or mandibular), and gingival infiltration with mepivacaine. Sedation quality was assessed by the surgeon from 1 (excellent) to 10 (surgery not feasible). A pain scoring system (EQUUS-FAP) was used to assess postoperative pain. Serum cortisol concentrations and locomotor activity (pedometers) were measured.Horses in BUP and BUT required a median detomidine infusion rate of 30.2 μg/kg/h (20 to 74.4 μg/kg/h) and 32.2 μg/kg/h (20 to 48.1 μg/kg/h), respectively (P = 0.22). Horses in the BUP group had better sedation quality (P < 0.05) during surgery and higher step counts (P < 0.001) postoperatively. Buprenorphine combined with detomidine provided a more reliable sedation than butorphanol. However, the EQUUS-FAP pain scale became unreliable because of BUP-induced excitement behavior.     

华南地区覆盖旱种水稻节水及其水分利用效率研究

大田试验条件下设置常规水稻(T11)、覆膜旱作水稻(T12)、覆草旱作水稻(T13)和裸地旱作水稻(T14)4个处理,研究旱作水稻的节水效率及水分利用效率。水稻本田期T11用水总量545.40 mm,显著高于各旱作处理水稻,以此为参照,T12、T13和T14节水效率分别为35.1%、22.8%和21.2%。以裸地旱作处理T14为参照,T12节水率17.7%,而T13无明显节水效果。旱作水稻的节水效果主要发生在水稻移栽后前2个月,之后无明显节水效果。各处理以籽粒产量/耗水量为基础计算的水分利用效率(WUE),T12、T13、T14和T11处理分别为1.47、1.31、1.21和1.05 g/kg,以干物质量/耗水量为基础计算的WUE各处理之间的趋势与以籽粒产量/耗水量计算的WUE基本一致。     

Dissolved and colloidal phosphorus fluxes in forest ecosystems—an almost blind spot in ecosystem research

Understanding and quantification of phosphorus (P) fluxes are key requirements for predictions of future forest ecosystems changes as well as for transferring lessons learned from natural ecosystems to croplands and plantations. This review summarizes and evaluates the recent knowledge on mechanisms, magnitude, and relevance by which dissolved and colloidal inorganic and organic P forms can be translocated within or exported from forest ecosystems. Attention is paid to hydrological pathways of P losses at the soil profile and landscape scales, and the subsequent influence of P on aquatic ecosystems. New (unpublished) data from the German Priority Program 1685 “Ecosystem Nutrition: Forest Strategies for limited Phosphorus Resources” were added to provide up‐to‐date flux‐based information. Nitrogen (N) additions increase the release of water‐transportable P forms. Most P found in percolates and pore waters belongs to the so‐called dissolved organic P (DOP) fractions, rich in orthophosphate‐monoesters and also containing some orthophosphate‐diesters. Total solution P concentrations range from ca. 1 to 400 µg P L^?1, with large variations among forest stands. Recent sophisticated analyses revealed that large portions of the DOP in forest stream water can comprise natural nanoparticles and fine colloids which under extreme conditions may account for 40–100% of the P losses. Their translocation within preferential flow passes may be rapid, mediated by storm events. The potential total P loss through leaching into subsoils and with streams was found to be less than 50 mg P m^?2 a^?1, suggesting effects on ecosystems at centennial to millennium scale. All current data are based on selected snapshots only. Quantitative measurements of P fluxes in temperate forest systems are nearly absent in the literature, probably due to main research focus on the C and N cycles. Therefore, we lack complete ecosystem‐based assessments of dissolved and colloidal P fluxes within and from temperate forest systems.     

Segregation of microsatellite loci in second generation hybrid striped bass (<Emphasis Type="Italic">Morone saxatilis</Emphasis> × <Emphasis Type="Italic">Morone chrysops</Emphasis>)

Within the framework of a larger project aimed to assess the potential of second generation hybrid striped bass for German aquaculture the genotypic segregation of five microsatellite loci was analysed in two progeny lots (n = 74 and 76, respectively). There was no consistent correlation between microsatellite genotypes and phenotypic category (white bass, hybrid, or striped bass). None of the individuals expressed neither only white bass nor only striped bass genotypes at all five loci. On the other hand, only hybrid genotypes at all five loci were detected in three individuals of lot 1 and four individuals of lot 2. Single loci tests for conformity of microsatellite genotypic segregation with Mendelian rules revealed significant deviations (P < 0.05) in four cases for lot 1 and in three cases for lot 2. If pooled over all five loci, both lots displayed highly significant deviations (P < 0.01) with an excess of hybrid genotypes and a deficiency of white bass genotypes. It is concluded that stabilizing selection performed on hybrid genotypes might be a suitable approach for practical aquaculture in Europe if the goal is to become independent of first generation hybrid fry supply and/or if establishing domesticated brood stocks of both parental species is impossible. However, more detailed studies on the characteristics and performance of multiple hybrid generations are needed.     

Panagrellus redivivus mass produced on solid media as live food for Litopenaeus vannamei larvae

The free‐living soil nematode Panagrellus redivivus is well known to be an excellent food source for first feeding fish larvae. It represents an alternative to the highly expensive Artemia, which is commonly used. The lack of a proper method for mass production of P. redivivus has prevented its wider use in commercial hatcheries. A new cultivation method allows the production of a sufficient quantity of nematodes to deliver a standardized and permanently available live food of high quality, throughout the larval rearing period. In two experiments – carried out at the Centro de Investigación en Alimentación y Desarrollo, Mexico – several feeding regimes were established to prove the quality of the mass produced P. redivivus for larvae of Litopenaeus vannamei, the Pacific white shrimp. Two different nematode treatments were compared with a no‐feed group and a control group that was fed with Artemia. All treatments had an additional algal co‐feed and were run in five replicates. Panagrellus redivivus was cultured on two different media (wheat/corn flour and oat flour) to compare these for their suitability as high‐quality live food for the larvae. Shrimp fed nematodes grown on wheat/corn medium reached the postlarval stage earlier than those from other treatments. The nematode treatments showed promising results; however, further research is needed on the development of improved culture media or enrichment methods to further increase the nutritional value of P. redivivus.     

Ultrasonographic characterization of the urinary bladder in sows with and without urinary tract infection

The urinary bladders of sows (n=10) without urinary tract infection (UTI) were longitudinally transrectally scanned after emptying and refilling with 200, 400, 600 and 800mL saline, and a volume dependence was found for bladder depth (BD), dorsal (dWT) and ventral wall thicknesses (vWT), wall regularity (WR) and mucosal wall surface (mWS). When another 31 sows without and 15 with UTI (as defined on the basis of high bacterial count and macroscopic/biochemical urine abnormalities) were compared for these parameters using BD as volume equivalent, no differences were found. Sows with UTI more often had moderate to high amounts of sediment than animals without UTI. Ultrasonographic assessment of dWT, vWT, WR and mWS of the urinary bladder of sows requires knowledge of bladder volume, and BD may be used as a volume equivalent. However, the parameters are inappropriate for the diagnosis of UTI as defined in this study, while moderate/high amounts of sediment seem to be indicative. Sediment can be visualized by transrectal scanning, but this is also possible using the transcutaneous route.     

Effect of dexmedetomidine and xylazine followed by MK-467 on gastrointestinal microperfusion in anaesthetized horses

Objective

To compare the effects of MK-467 during isoflurane anaesthesia combined with xylazine or dexmedetomidine on global and gastrointestinal perfusion parameters.

Über die Sorptionseigenschaften von Waldböden bezüglich gelöster organischer Substanzen

About the sorption of dissolved organic matter to forest soils This investigation characterizes the major forest soils of the temperate climatic zones (leptosols, vertisols, cambisols, luvisols, podzols, stagnosols, gleysols) as sorbents for dissolved organic matter (DOM). Sorption isotherms were obtained for 135 soil horizons from 36 profiles. When solutions containing no DOC were added, the release of dissolved organic carbon (DOC) was highest for horizons rich in organic C (A and Bh horizons). In subsoil horizons DOC release was much lower. Most of the investigated top soils (A and E horizons) and Bh, Bg, and C horizons showed a weak DOC sorption. This was caused by low contents of sorbents (clay and sesquioxides) and/or high contents of organic C. Organic C seems to reduce the DOC sorption by occupying binding sites. Subsoils rich in clay and sesquioxides like Bs, Bt, and Bw horizons showed a strong retention of DOC. Under the aerobic conditions of the experiments, some of the subsoils of stagnosols and gleysols also showed a strong sorption of DOC. However, in sorption experiments conducted after an anaerobic incubation, the DOC sorption decreased significantly.     

The global circulation of seasonal influenza A (H3N2) viruses

Antigenic and genetic analysis of the hemagglutinin of approximately 13,000 human influenza A (H3N2) viruses from six continents during 2002-2007 revealed that there was continuous circulation in east and Southeast Asia (E-SE Asia) via a region-wide network of temporally overlapping epidemics and that epidemics in the temperate regions were seeded from this network each year. Seed strains generally first reached Oceania, North America, and Europe, and later South America. This evidence suggests that once A (H3N2) viruses leave E-SE Asia, they are unlikely to contribute to long-term viral evolution. If the trends observed during this period are an accurate representation of overall patterns of spread, then the antigenic characteristics of A (H3N2) viruses outside E-SE Asia may be forecast each year based on surveillance within E-SE Asia, with consequent improvements to vaccine strain selection.