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81.
We examined the principal differences in photosynthetic characteristics between sun and shade foliage and determined the relative importance of biochemical and stomatal limitations during photosynthetic induction. Temperate-zone broadleaf and conifer tree species, ranging widely in shade tolerance, were investigated from one locality in the Czech Republic. The study species included strongly shade-tolerant Abies alba Mill. and Tilia cordata Mill., less shade-tolerant Fagus sylvatica L. and Acer pseudoplatanus L. and sun-demanding Picea abies (L.) Karst. In the fully activated photosynthetic state, sun foliage of all species had significantly higher maximum CO(2) assimilation rates, maximum stomatal conductance and maximum rates of carboxylation than shade foliage. Compared with shade leaves, sun leaves had significantly higher nocturnal stomatal conductances. In all species, shade foliage tended to have higher induction states 60 s after leaf illumination than sun foliage. Sun and shade foliage did not differ in the rate of disappearance of the transient biochemical limitation during the induction phase. Longer time periods were required to reach 90% photosynthetic induction and 90% stomatal induction in sun foliage than in shade foliage of the less shade-tolerant F. sylvatica and A. pseudoplatanus and in sun-demanding P. abies; however, in sun foliage of the strongly shade-tolerant species T. cordata and A. alba, the time needed for photosynthetic induction was similar to, or less than, that for shade foliage. Shade but not sun needles of P. abies and A. alba had significantly slower induction kinetics than the broadleaf tree species. Among species, the sun-demanding P. abies exhibited the shortest stomatal induction times in both sun and shade leaves. Independently of shade tolerance ranking, the transient stomatal and total limitations that characterize photosynthetic induction were relieved significantly earlier in shade foliage than in sun foliage. Sun foliage generally exhibited a hyperbolic photosynthetic induction response, whereas a sigmoidal induction response was more frequent in shade foliage. The different relative proportions of transient biochemical and stomatal limitations during photosynthetic induction in sun and shade foliage indicate an essential role of stomata in photosynthetic limitation during induction, mainly in shade foliage, with a consequent influence on the shape of the photosynthetic induction curve. 相似文献
82.
Nir Melnikov Yehuda Kamari Michal Kandel-Kfir Iris Barshack Ami Ben-Amotz Dror Harats Aviv Shaish Ayelet Harari 《Marine drugs》2022,20(7)
Vitamin A and provitamin A carotenoids are involved in the regulation of adipose tissue metabolism and inflammation. We examined the effect of dietary supplementation using all-trans and 9-cis β-carotene-rich Dunaliella bardawil alga as the sole source of vitamin A on obesity-associated comorbidities and adipose tissue dysfunction in a diet-induced obesity mouse model. Three-week-old male mice (C57BL/6) were randomly allocated into two groups and fed a high-fat, vitamin A-deficient diet supplemented with either vitamin A (HFD) or β-carotene (BC) (HFD-BC). Vitamin A levels in the liver, WATs, and BAT of the HFD-BC group were 1.5–2.4-fold higher than of the HFD group. BC concentrations were 5–6-fold greater in BAT compared to WAT in the HFD-BC group. The eWAT mRNA levels of the Mcp-1 and Cd68 were 1.6- and 2.1-fold lower, respectively, and the plasma cholesterol and triglyceride concentrations were 30% and 28% lower in the HFD-BC group compared with the HFD group. Dietary BC can be the exclusive vitamin A source in mice fed a high-fat diet, as shown by the vitamin A concentration in the plasma and tissues. Feeding BC rather than vitamin A reduces adipose tissue macrophage recruitment markers and plasma lipid concentrations. 相似文献
83.
84.
Ulrike Auer J. Peter Schramel Yves P. Moens Martina Mosing Christina Braun 《Veterinary anaesthesia and analgesia》2019,46(2):200-208
Objective
To assess changes in the distribution in pulmonary ventilation in anaesthetized ponies using electrical impedance tomography (EIT).Study design
Prospective experimental study.Animals
A group of eight adult pony geldings.Methods
General anaesthesia was induced and maintained using isoflurane in oxygen with volume-controlled ventilation [tidal volume (VT) (10 mL kg?1), respiratory rate (8–12 breaths minute?1)] to maintain end-tidal carbon dioxide between 35 and 40 mmHg (4.66–5.32 kPa). Regional distribution of ventilation was assessed with EIT (plane of fifth to sixth intercostal space) at 30, 60 and 90 minutes after intubation. The resulting functional images were divided into four regions of interest (ROI, A–D) to determine: 1) the ratio of VT distribution between dependent to nondependent lung (D/ND) and 2) changes in distribution within the lungs in the latero-lateral direction. The centre of ventilation (COV) was calculated. The dimension of the chest in the latero-lateral (W) and dorso-ventral (H) direction was measured at the height of the withers and the W/H ratio was calculated. The influence of time on the D/ND ratio, COV and ROI A–D were analysed with anova followed by post hoc Bonferroni tests. Pearson correlation coefficient and the coefficient of determination (r2) were calculated to evaluate the relationship between the W/H ratio and D/ND ratio, and COV. Statistical significance was set at p < 0.05.Results
The median D/ND ratio (T30–T90) was 0.67 (0.40–1.01) and for COV 31.15% (11.20–45.20), confirming the expected uneven distribution of ventilation. The D/ND ratio had a moderate negative correlation with the W/H ratio (r = ?0.68, r2 = 0.46, p < 0.001), while the COV did not correlate with the W/H ratio (r = ?0.04).Conclusions and clinical relevance
Uneven ventilation in mechanically ventilated right laterally recumbent anaesthetized ponies occurs within 30 minutes and changed little over the following 60 minutes. 相似文献85.
86.
Context
Objective identification of locations on transportation networks, where animal-vehicle collisions (AVC) occur more frequently than expected (hotspots), is an important step for the effective application of mitigation measures.Objectives
We introduce the KDE+ software which is a programmed version of the KDE+ method for effective identification of traffic accident hotspots. The software can be used in order to analyze animal-vehicle collision data.Methods
The KDE+ method is based on principles of Kernel Density Estimation (KDE). The symbol ‘+’ indicates that the method allows for the objective selection of significant clusters and for the ranking of the hotspots. It is also simultaneously applicable to an unlimited number of road segments.Results
We applied the KDE+ method to the entire Czech road network. The hotspots were ranked according to their significance. The resulting hotspots represent a short overall road length which should require a more detailed assessment in the field. The 100 most important clusters of AVC represent, for example, only 19.7 km of the entire road network (37,469 km).Conclusions
We present an objective method for hotspots identification which can be used for AVC data. This method is unique because it determines the significance level of hotspots in an objective way. The prioritization of hotspots allows a transportation manager to effectively allocate resources to a feasible number of identified hotspots. We describe the software, data preparation and present the KDE+ application to AVC data.87.
Oliver Schmied Gernot Scharf Monika Hilbe Ulrike Michal Kamil Tomsa Frank Steffen 《Veterinary radiology & ultrasound》2008,49(4):343-349
The clinical, neuropathologic, and magnetic resonance (MR) imaging features in four cats with necrosis of the hippocampus and piriform lobe are described. All cats had acute generalized seizures and behavioral changes including aggression, salivation, polyphagia, and disorientation. Routine hematologic, serum chemistry, and cerebrospinal fluid analyses were normal. MR imaging abnormalities were restricted to the area of the hippocampus and piriform lobe. The lesions were T2-hyperintense, T1-hypointense, and were characterized by various degrees of contrast enhancement. Lesions were consistent with necrotizing encephalitis. Two cats were euthanized and underwent postmortem examination within a week after MR imaging due to the lack of response to antiepileptic drug therapy and progressive neuropathy. The remaining two cats lived for about four months and were then euthanized because of persistent behavioral and neurologic signs; only one of these cats underwent postmortem examination with histopathologic examination. Histopathological findings were typical of severe, diffuse, bilateral symmetric necrosis, and degeneration of neurons in the hippocampus and piriform lobe, but an etiologic agent was not apparent. This apparently unique feline syndrome, now reported in Switzerland and Italy, has no known cause at this time. 相似文献
88.
The prevalence of Middle East respiratory syndrome coronavirus (MERS‐CoV) antibodies in dromedary camels in Israel
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Jennifer L. Harcourt Nir Rudoler Azaibi Tamin Eyal Leshem Michal Rasis Michael Giladi Lia M. Haynes 《Zoonoses and public health》2018,65(6):749-754
Middle East respiratory syndrome coronavirus, MERS‐CoV, was identified in Saudi Arabia in 2012, and as of January 29, 2018, there were 2,123 laboratory‐confirmed MERS‐CoV cases reported to WHO (WHO, 2018, https://www.who.int/emergencies/mers-cov/en/ ). Multiple studies suggest that dromedary camels are a source for human MERS‐CoV infection. MERS‐CoV‐specific antibodies have been detected in the serum of dromedary camels across Northern Africa and across the Arabian Peninsula. Israel's geographic location places Israel at risk for MERS‐CoV infection. To date, MERS‐CoV‐related illness has not been reported and the burden of MERS‐CoV infection in the Israeli population is unknown. The seroprevalence of MERS‐CoV‐specific antibodies in Israeli dromedary camels is unknown. The objective of this study was to determine the prevalence of MERS‐CoV seropositivity in dromedary camels in Israel. The prevalence of MERS‐CoV antibodies in Israeli camels was examined in 71 camel sera collected from four farms across Israel by MERS‐CoV‐specific microneutralization (Mnt) assay and confirmed by MERS‐CoV‐specific immunofluorescence assay (IFA). Although this study cannot rule out potential antibody cross‐reactivity by IFA, the presence of bovine coronavirus‐specific antibodies do not appear to impact detection of MERS‐CoV antibodies by Mnt. MERS‐CoV neutralizing antibodies were detectable in 51 (71.8%) camel sera, and no association was observed between the presence of neutralizing antibodies and camel age or gender. These findings extend the known range of MERS‐CoV circulation in Middle Eastern camels. The high rate of MERS‐CoV‐specific antibody seropositivity in dromedary camels in the absence of any reported human MERS cases suggests that there is still much to be learned about the dynamics of camel‐to‐human transmission of MERS‐CoV. 相似文献
89.
90.
Dror M Sinyakov MS Okun E Dym M Sredni B Avtalion RR 《Veterinary immunology and immunopathology》2006,109(3-4):279-287
Experimental handling stress (EHS) was applied to clinically asymptomatic farmed goldfish (Carassius auratus L.). EHS affected the gills and skin integrity of the fish and was accompanied by increased levels of plasma glucose, cortisol and interleukin-10 (IL-10). EHS application was followed by highly significant enhancement of the rate of infection with a virulent Aeromonas salmonicida isolate. Cumulative ulceration at the initial phase of the ensuing goldfish ulcerative disease (GUD) evidenced a facilitating role of EHS in the onset of GUD. Host susceptibility to the pathogen increased from 40% in unstressed fish to 90% in the stressed fish. A. salmonicida could be reisolated from the early-stage skin lesions only, whereas opportunistic strains, other than A. salmonicida (A. sobria and A. hydrophila), were recovered from progressive-stage ulcers. The implication of these findings in fish aquaculture is discussed. 相似文献