The influence of butorphanol dose on characteristics of xylazine-butorphanol-propofol anesthesia in horses at altitude

OBJECTIVE: To characterize behavioral and physiological responses to short-term, unsupplemented intravenous (IV) anesthesia in healthy horses at high altitude (2240 m), and to test the hypothesis that the dose of butorphanol modifies the response of the horse to propofol anesthesia following xylazine pre-medication. STUDY DESIGN: Randomized prospective butorphanol dose cross-over experimental design. Animals Eight healthy horses, 13 +/- 6 (mean +/- SD) years of age, and weighing 523 +/- 26 kg. METHODS: Each horse was anesthetized three times with at least 3 weeks between each anesthesia. After collecting pre-drug data, xylazine (0.5 mg kg(-1)) was given IV. Five minutes later butorphanol was given IV according to a randomized order of three doses: 0.025, 0.05 and 0.075 mg kg(-1). Five minutes later, anesthesia was induced with propofol, 2 mg kg(-1) IV. Data on heart rate (HR) and respiratory rate (f(r)), mean arterial blood pressure, P(a)O(2), P(a)CO(2) and pH(a) were collected before, during and for 60 minutes following anesthesia, and quality of induction and recovery was scored. RESULTS: The pre-drug values for the three butorphanol groups did not differ. The combined pre-drug values from the 24 studies were HR, 33 +/- 7 beats minute(-1); f(r), 11 +/- 3 breaths minute(-1); P(a)O(2), 67 +/- 7 mmHg; P(a)CO(2), 36 +/- 4 mmHg; and pH(a), 7.42 +/- 0.04. Five minutes after anesthetic induction P(a)O(2) decreased and P(a)CO(2) increased 14.5 +/- 7.7 and 5.1 +/- 4.9 mmHg, respectively, but returned to pre-drug levels within 15 minutes of anesthetic recovery. There were no significant butorphanol dose-related differences in physiological results, anesthetic induction and recovery quality scores or recovery time. CONCLUSIONS AND CLINICAL RELEVANCE: Dose of butorphanol did not markedly influence study results. Notably, low P(a)O(2) values related to geographic location of study and general anesthesia indicates a narrow margin of error for hypoxemia-related complications in anesthetized horses breathing unsupplemented air at high altitude.     

The increase in prolactin-secreting cells in incubating chicken hens can be mimicked by extended treatment of pituitary cells in vitro with vasoactive intestinal polypeptide (VIP)

Incubation of eggs by birds and lactation in mammals are regulated by pituitary prolactin (PRL) and associated with an increase in pituitary PRL-producing cells or lactotrophs. However, the mechanisms controlling this increase in lactotroph numbers are not known. PRL secretion in birds is regulated by vasoactive intestinal polypeptide (VIP). This study was designed to determine whether VIP treatment could modulate lactotroph abundance in culture. Anterior pituitary cells were isolated from laying Japanese White Silkie hens and cultured for 2 or 6 days in the absence or presence of VIP. PRL-secreting cells were identified by reverse hemolytic plaque assay. Treatment with VIP for 6 days substantially increased the abundance of PRL-secreting cells from 47.5% under basal conditions to 70.6% of all pituitary cells following VIP stimulation. However, 2-day VIP treatment had no effect. Furthermore, the extent to which the hens were allowed to accumulate eggs in a clutch prior to isolation of the pituitaries did not affect the lactotroph response to VIP in vitro. These findings indicate that chronic VIP stimulation may be responsible for the increased abundance of lactotrophs found in the pituitary glands of incubating hens.     

Evaluation of cassava germplasm for drought tolerance under field conditions

The development of cassava (Manihot esculenta Crantz) with a high yield under water-deficit conditions is one of the goal of the breeding programs. The objective of this study was to evaluate the performance and to select cassava accessions based on drought tolerance indices and productive potential under water stress. Forty-nine accessions were evaluated for five agronomic traits (plant height—PH, root yield—RoY, shoot yield—ShY, harvest index—HI; and dry matter content of roots—DMC) under full irrigation conditions and drought stress (DS). The accessions were selected based on: (i) high yield under drought conditions (HY-DS) and (ii) high drought tolerance (Dr-To) based on six different indices. Overall, water stress dramatically reduced the traits’ means (RoY—72.98%, ShY—54.95%, DMC—26.15%, HI—31.05%, and PH—32.95%). Low coincidence among the top ten accessions was identified based on HY-DS and Dr-To criteria. Therefore, considering only the most important traits (RoY and ShY), five accessions (BGM0815, BGM0598, 9624-09, BGM0818, and BRS Formosa) presented high HY-DS. In contrast, to Dr-To criterion, eight and nine accessions were selected for high yield of the aerial part (ShY and PH) and roots (RoY and DMC), respectively. The mean productivity, geometric mean productivity, and drought tolerance indices were the most promising to identify genotypes with high agronomic attributes, while drought susceptibility index, susceptibility, and yield stability index were suitable to identify the most drought tolerant accessions. This set of selected accessions can be used in breeding programs aimed at high yield and drought tolerance.     

The use of gelatine in long‐term storage (up to 48 hr) at 5°C preserves the pre‐freezing and post‐thawing quality of brown bear sperm

Sedimentation of spermatozoa occurs during long‐term liquid storage and this may produce deleterious changes. Our aim was to apply gelatine supplementation during long‐term pre‐freezing storage of bear sperm, applying final dilution and 6% glycerol at room temperature and cool in straws. We tested four models of sperm storage using a 1:1 dilution in TTF‐ULE‐Bear extender (TesT‐fructose‐egg yolk‐glycerol 6%): (i) second 1:1 dilution at room temperature (RT), cooling at 5°C in a tube and final dilution (100 × 10⁶ sperm ml^?1) (Standard); (ii) final dilution at RT and cooling in a tube (FD‐Tube); (iii) final dilution at RT and cooling in 0.25 ml plastic straw (FD‐Straw); and (iv) final dilution at RT in extender supplemented with 1.5% gelatine (Gelatine) and cooling in a 0.25 ml plastic straw. A Standard sample was stored at 5°C for 1 hr (Control); the rest of the samples (Standard, FD‐Tube, FD‐Straw, Gelatine) were stored for 24 or 48 hrs before freezing (100 × 10⁶ sperm ml^?1, glycerol 6%). The quality of the samples was assessed for motility by CASA, and viability (SYBR‐14/propidium iodide‐PI‐; VIAB), acrosomal status (PNA‐FITC/PI; iACR) and apoptotic status (YO‐PRO‐1/PI; YOPRO‐) by flow cytometry. At pre‐freezing, after 48 hr, Gelatine showed significantly higher viability (for VIAB and YOPRO‐) and progressiveness (PM, LIN and STR). At 48 hr, Gelatine showed similar YOPRO‐, iACR, LIN, STR and ALH respect to Control. At both 24 and 48 h post‐thawing, Gelatine sample had similar scores for YOPRO‐, iACR, LIN, STR, WOB and VIAB (only 24 hr) when compared with Control, and lower for TM, PM, rapidPM, VAP and ALH. No differences were found among others experimental groups with respect to Control. In conclusion, gelatine could be a suitable alternative to preserve the viability and progressive motility of brown bear ejaculates during long‐term pre‐freezing storage at 5°C.     

Terrestrial gamma-ray flashes observed up to 20 MeV

Terrestrial gamma-ray flashes (TGFs) from Earth's upper atmosphere have been detected with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) satellite. The gamma-ray spectra typically extend up to 10 to 20 megaelectron volts (MeV); a simple bremsstrahlung model suggests that most of the electrons that produce the gamma rays have energies on the order of 20 to 40 MeV. RHESSI detects 10 to 20 TGFs per month, corresponding to approximately 50 per day globally, perhaps many more if they are beamed. Both the frequency of occurrence and maximum photon energy are more than an order of magnitude higher than previously known for these events.     

Contribution of human alpha-defensin 1, 2, and 3 to the anti-HIV-1 activity of CD8 antiviral factor

It has been known since 1986 that CD8 T lymphocytes from certain HIV-1-infected individuals who are immunologically stable secrete a soluble factor, termed CAF, that suppresses HIV-1 replication. However, the identity of CAF remained elusive despite an extensive search. By means of a protein-chip technology, we identified a cluster of proteins that were secreted when CD8 T cells from long-term nonprogressors with HIV-1 infection were stimulated. These proteins were identified as alpha-defensin 1, 2, and 3 on the basis of specific antibody recognition and amino acid sequencing. CAF activity was eliminated or neutralized by an antibody specific for human alpha-defensins. Synthetic and purified preparations of alpha-defensins also inhibited the replication of HIV-1 isolates in vitro. Taken together, our results indicate that alpha-defensin 1, 2, and 3 collectively account for much of the anti-HIV-1 activity of CAF that is not attributable to beta-chemokines.     

Temporal changes in nitrogen acquisition of Japanese black pine （Pinus thunbergii） associated with black locust （Robinia pseudoacacia）

The alien woody legume, black locust(Robinia pseudoacacia), has invaded Japanese black pine(Pinus thunbergii) forests located in Japan's coastal plain and hill regions where gaps are formed in pine forests after nematode infestation. Nitrogen fixation by legumes accelerates N cycling in forest ecosystems. We studied temporal change in the annual tree-ring resolution N stable isotope composition(δ15N, a per mil deviation of δ15N/14 N ratio, relative to atmospheric N2δ15N=0‰) at two natural locations of Japanese black pine forest with black locust that differed in the time since black locust establishment(Shohnai in northeast and Kita-Kyushu in southwest Japan). Analyzed tree-rings covered the period from 1990/1992 to 2009. N acquisition by Japanese black pine from black locust N input to the soil was evidenced by temporal shifting of N stable isotope composition on the annual pine tree rings. With progressive development of the forest stand, δ15N values of earlier tree-rings δ15N of-5‰) from black pine associated with black locust shifted towards values similar to those of black locust δ15N values nearly to-1‰), which suggests acquisition of N by N2 fixation(Shohnai site). In contrast, in a forest where black locust had settled for two or three generations, in a black pine stand(Kita-Kyushu site), longer periods of N enrichment in the soil were reflected in the elevated tree-ring δ15N values of newly established black pine trees. Based on tree-ring δ15N data from the Shohnai site, we determined that about 10 years after black locust establishment, soil N had already been enriched by black locust N, this, in turn, contributed to N fertilization of surrounding trees in mixed stands.     

The nature and spatial variability of lowland savanna soils: Improving the resolution of soil properties to support land management policy

A fresh approach is presented to address the increasingly urgent need for alternative land management strategies in savannas. We illustrate how fine‐scale information of soil characteristics can be used to enable a more precise delimitation of sites suitable for different forms of land stewardship, including agro‐pastoral activities, forestry, biodiversity and tourism. By collating data from previous soil surveys, and augmenting this with targeted new surveys, we produce the first national data set of soil properties for the lowland savannas of Belize. Most of these soils are typical of savanna soils worldwide, that is acidic (mean surface pH = 5.7), nutrient‐poor (mean surface total exchangeable bases [TEB] = 3.4 cmol kg^?1) and coarse‐textured (mean surface clay = 13.0%). Nevertheless, there is a marked spatial variability across the country in these soil properties. Some soils exhibit unusually high subsurface clay fractions (max = 73%), whilst other sites have exceptionally high pH in lower horizons (max = 8.4). Cluster analysis is used to group sites with similar soil properties. Across 79 sites, there is a clear division between soils with high clay percentages and those with coarser textures. These are sub‐divided into five groups based on further differences in parent material, chemical properties and site characteristics. Mapping the locations of these groups enables more specific land use recommendations to be made. This ability to make targeted land use recommendations from fine‐scale soil information represents an advance over the previous national land use policy, where all savanna lands were considered unsuitable for any form of agriculture. This approach could be applied to marginal savannas worldwide.