Diameter and death of whorl and interwhorl branches in Atlas cedar (<Emphasis Type="Italic">Cedrus atlantica</Emphasis> Manetti): a model accounting for acrotony

• Introduction   

Branch size and branch status (dead or alive) are important characteristics closely related to tree growth and wood quality. The aim of this study was to design models for the diameter and status of branches in Atlas cedar (Cedrus atlantica Manetti).     

High-resolution computed tomography of the mammalian lung.

High-resolution computed tomography (HRCT) was performed in 21 isolated animal lungs, from 4 mammalian species (pigs, rabbits, dogs, sheep). Gross and subgross central and peripheral lung morphology was determined by HRCT. Three distinct types of lungs can be identified, principally based on the extent of interlobular septal development; the relationship of major vessels to airways; and the thickness of the visceral pleura. Type-I lung is found in pigs, sheep, and cattle; type-II lung is found in rabbits, dogs, cats, and monkeys; and type-III lung is found in human beings and horses. These mammalian lungs were compared with human lungs. The potential use of HRCT to investigate specific human lung diseases in the aforementioned species also was considered.     

Virulence and efficacy of different entomopathogenic nematode species against western flower thrips (Frankliniella occidentalis)

Virulence and efficacy of five species and strains of the entomopathogenic nematodes of the families Steinernematidae and Heterorhabditidae:Steinernema riobravis, Steinernema feltiae strains Ger. and UK, andHeterorhabditis bacteriophora strains HP88 and IS5, against the prepupal and pupal stages of the western flower thrips (WFT),Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), were investigated in the laboratory. Although all these nematodes controlled WFT to some extent, they differed in efficiency. The heterorhabditid nematodeH. bacteriophora strain HP88 was more specific to the soil-inhabiting WFT stages (36–49% thrips mortality). The steinernematid nematodesS. riobravis andS. feltiae strains Ger. and UK had only a slight effect (10% mortality) on prepupal and pupal populations of WFT, andH. bacteriophora strain IS5 had the least effect of all. A possible reason for such species variation is suggested and discussed.     

Experimental evaluation of four airway devices in anaesthetized New Zealand White rabbits

Objective

To compare airway management during induction of anaesthesia, spontaneous ventilation (SV) and controlled mechanical ventilation (CMV), using an endotracheal tube (ETT), laryngeal mask (LM), rabbit-specific supraglottic airway device (v-gel) or facemask (FM).

Nearby rainforest promotes coffee pollination by increasing spatio-temporal stability in bee species richness

Natural tropical forests are highly diverse and are known to contribute to forest-based services such as pollination of nearby crops. Landscape changes cause spatial and temporal bee community changes, but consequences how the community changes affect pollination is not well analyzed. This paper addresses the effects of rainforest distance and on site flower resources in agro-forests on spatial and temporal variation in pollinator communities and the consequences for coffee pollination.     

Intestinal stem cell replacement follows a pattern of neutral drift

With the capacity for rapid self-renewal and regeneration, the intestinal epithelium is stereotypical of stem cell-supported tissues. Yet the pattern of stem cell turnover remains in question. Applying analytical methods from population dynamics and statistical physics to an inducible genetic labeling system, we showed that clone size distributions conform to a distinctive scaling behavior at short times. This result demonstrates that intestinal stem cells form an equipotent population in which the loss of a stem cell is compensated by the multiplication of a neighbor, leading to neutral drift dynamics in which clones expand and contract at random until they either take over the crypt or they are lost. Combined with long-term clonal fate data, we show that the rate of stem cell replacement is comparable to the cell division rate, implying that neutral drift and symmetrical cell divisions are central to stem cell homeostasis.     

In vitro effects of very low levels of aflatoxin B₁ on free radicals production and bactericidal activity of bovine blood neutrophils

As one of the most potent and hazardous feed/food-originated mycotoxins, aflatoxin (AF) B? is regarded as a potent immunosuppressor in dairy cows. Neutrophils (PMN), as key effector cells against pathogens, have a high potential to kill engulfed microbes. To investigate the in vitro effects of very low doses of AFB? on blood PMN functions, we examined the effects of biologically relevant concentrations of AFB? on the phagocytosis and non-phagocytosis dependent luminol, representative of mainly intracellular free radicals, and isoluminol, representative of mainly extracellular free radicals, chemiluminescence (CL), necrosis and apoptosis of PMN. Isolated blood PMN from healthy dairy cows (n=12) were exposed to 0, 0.01, 0.05 and 0.5 ng/ml of AFB? for 0.5 and 18 h depending on the assay. Further, blood PMN of healthy dairy cows (n=8) were exposed to 0.5 ng/ml of AFB? for 3h and myeloperoxidase (MPO) activity, superoxide anion (O??) production, phagocytosis and killing activities against Staphylococcus (S.) aureus and Escherichia (E.) coli, were examined. Though the effect of extremely low doses of AFB? were less pronounced, at 0.5 ng/ml the production of free radicals was greatly enhanced, especially extracellularly. In contrast to isoluminol CL, the AFB?-treated PMN showed a remarkably impaired phagocytosis-depended luminol CL. PMN necrosis and apoptosis were not affected by AFB?. MPO activity, O?? production, phagocytosis rates and killing of E. coli and S. aureus by AFB?-treated PMN were significantly lower than those of non-treated ones. Our results show the extracellularly pro-oxidant and antiphagocytic properties of very low doses of AFB? for bovine PMN. The scope of the suppressive effects of the in vitro AFB? levels on cellular innate immune functions should be considered for high yielding dairy cows.