Earthworm (<Emphasis Type="Italic">Metaphire guillelmi</Emphasis>) effects on rice photosynthates distribution in the plant–soil system

An experiment was conducted to investigate the effects of earthworm (Metaphire guillelmi) activities on rice photosynthates distribution in plant–soil system through ¹⁴C pulse-labelling method. Rice was planted in pots, and maize straw was mulched on the surface with or without earthworms. Rice plants at tillering stage or heading stage were labelled with ¹⁴CO₂. Plant and soil were sampled 15 days after labelling at the tillering or heading stage and at harvest. Rice growth was inhibited by earthworms (M. guillelmi) at early stage, but the inhibition disappeared at later stage. Earthworms significantly (P < 0.01) increased the ¹⁴C percentage in root at day 15 after tillering stage labelling, but the effect disappeared at harvest. Earthworms (M. guillelmi) significantly (P < 0.01) increased the ¹⁴C percentage in root at day 15 after heading stage labelling and increased ¹⁴C percentage in soil at harvest. Earthworms decreased the percentages of total organic ¹⁴C (TO¹⁴C) present as microbial biomass ¹⁴C (MB¹⁴C) and increased the percentages of total organic ¹⁴C present as dissolved organic ¹⁴C (DO¹⁴C) at all sampling times. It is suggested that earthworms might alter the transfer of plant photosynthates from the aboveground to the belowground, and thus, soil active C pool. However, these data should be also confirmed in the field.     

Phenolic composition in grape (Vitis vinifera L. cv. Malbec) ripened with different solar UV-B radiation levels by capillary zone electrophoresis

The responses of Vitis vinifera L. cv. Malbec to different solar ultraviolet-B radiation (UV-B) levels were assessed in two contrasting situations, under sunlight with full UV-B (+UV-B) and filtered UV-B (-UV-B), in three different locations at 500, 1000, and 1500 m above sea level (asl). To evaluate the effects of radiation, a simple, accurate, and rapid method for the separation and simultaneous determination of representative phenolic compounds in grape berry skins by capillary zone electrophoresis was developed. Separation was carried out in less than 20 min with 20 mM sodium tetraborate buffer containing 30% methanol, pH 9.00. The procedure is fast and reliable, and extracted grape berry skins can be directly analyzed without prior sample cleanup procedure. Berry skins from the +UV-B treatment at 1500 m asl showed the highest levels of total polyphenols anthocyanins, and resveratrol, compared with the -UV-B treatment at this altitude.     

Susceptibility evaluation of Picea abies and Cupressus lusitanica to the pine wood nematode (Bursaphelenchus xylophilus)

Pine wilt disease (PWD), recently introduced into Europe, is caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus and is a devastating illness that affects mainly pine trees. It is known that the PWN is capable of infecting other conifers; however, there is currently no information on which other plant species may be susceptible to PWD. In this study, the potential susceptibility of two common species of European forests, Picea abies and Cupressus lusitanica, to PWN was assessed through the monitoring of visual external symptoms, dimension and localization of the nematode population in stems, quantification of total chlorophyll, total soluble phenolics and lignin, at 7, 14, 21 and 28 days after inoculation. The degree of susceptibility was established through the comparison of symptoms with Pinus pinaster, a well‐known PWN host. Furthermore, the stem ultrastructure of P. abies, C. lusitanica and Pn. pinaster was analysed by scanning electron microscopy. The results suggest that P. abies and C. lusitanica are resistant to PWN, and that lignin biosynthesis in these species is affected at an early stage of the infestation. Nevertheless, P. abies seems to be a compatible host that could act as a repository for PWN.     

Evaluation of analgesic and physiologic effects of epidural morphine administered at a thoracic or lumbar level in dogs undergoing thoracotomy

ObjectiveTo evaluate the analgesic and physiological effects of epidural morphine administered at the sixth and seventh lumbar or the fifth and sixth thoracic vertebrae in dogs undergoing thoracotomy.Study designProspective, randomized, blinded trial.AnimalsFourteen mixed-breed dogs, weighing 8.6 ± 1.4 kg.MethodsThe animals received acepromazine (0.1 mg kg^?1) IM and anesthesia was induced with propofol (4 mg kg^?1) IV. The lumbosacral space was punctured and an epidural catheter was inserted up to the region between the sixth and seventh lumbar vertebrae (L, n = 6) or up to the fifth or sixth intercostal space (T, n = 8). The dogs were allowed to recover and after radiographic confirmation of correct catheter position, anesthesia was reinduced with propofol IV and maintained with 1.7% isoflurane. Following stabilization of monitored parameters, animals received morphine (0.1 mg kg^?1) diluted in 0.9% NaCl to a final volume of 0.25 mL kg^?1 via the epidural catheter, and after 40 minutes, thoracotomy was initiated. Heart rate and rhythm, systolic, mean and diastolic arterial pressures, respiratory rate, arterial hemoglobin oxygen saturation, partial pressure of expired CO₂ and body temperature were measured immediately before the epidural administration of morphine (0 minute) and every 10 minutes during the anesthetic period. The Melbourne pain scale and the visual analog scale were used to assess post-operative pain. The evaluation began 3 hours after the epidural administration of morphine and occurred each hour until rescue analgesia.ResultsThere were no important variations in the physiological parameters during the anesthetic period. The post-operative analgesic period differed between the groups, being longer in T (9.9 ± 1.6 hours) compared with L (5.8 ± 0.8 hours).ConclusionsThe use of morphine, at a volume of 0.25 mL kg^?1, administered epidurally over the thoracic vertebrae provided longer lasting analgesia than when deposited over the lumbar vertebrae.Clinical relevanceThe deposition of epidural morphine provided longer lasting analgesia when administered near to the innervation of the injured tissue without increasing side effects.     

Bayesian estimation of cluster-level test accuracy based on different sampling schemes

We develop Bayesian models to estimate cluster-level test characteristics, sensitivity, specificity, prevalence, and predictive values, based on four different sampling schemes: a single test case and three sequential test cases. The corresponding cluster-level characteristics are calculated and compared for different sample sizes, sampling schemes, individual-level sensitivities, specificities, and cut-off values. We compared posterior estimates of individual-level and cluster-level characteristics for these four sampling schemes with simulated data. Two illustrations, one for Johne’s disease in cattle and another for Salmonella in pig herds, are used to demonstrate application of the methods.     

Do pine plantations provide mycorrhizal inocula for seedlings establishment in grasslands from Patagonia,Argentina?

We investigated if Pinus ponderosa plantations in Patagonia are able to produce viable mycorrhizal inocula towards adjacent grasslands, which only harbor endomycorrhizal vegetation. We hypothesized that these inocula have the potential to contribute to the establishment of naturally disseminated seedlings. Also, we determined the main fungal taxa involved in this process. Seven plantations in the onset of their reproductive phase and located in the Patagonian native forest/steppe ecotone (Argentina) were selected. Soil samplings were obtained at nine points along a 450 m long, W-E transect established in each plantation. Soil bioassays were performed in a greenhouse, with P. ponderosa seedlings acting as hosts for mycorrhizal inocula present in soil samples, during 12 months. Mycorrhization percentage, morphotype richness and morphotype composition was determined through morphological evaluation. Viable ecto- and ectendomycorrhizal inocula were found disseminated outside plantations. The amount of mycorrhizal inoculum followed a decreasing function with distance to plantation edges. Mycorrhizal fungal genus Rhizopogon and “E-strain” mycorrhizal types appeared as pioneering taxa regarding seedlings colonization, being the most persistent and frequent symbionts found. Plantations, thus, facilitate the surrounding terrain for newcoming seedlings through the dispersion of mycorrhizal fungal inocula.     

Results of molecular analysis of an archaeological hemp (<Emphasis Type="Italic">Cannabis sativa</Emphasis> L.) DNA sample from North West China

Hemp (Cannabis sativa L.) cultivation and utilization is an ancient practice to human civilization. There are some controversies on the origin and subsequent spread of this species. Ancient plant DNA has proven to be a powerful tool to solve phylogenetic problems. In this study, ancient DNA was extracted from an archaeological specimen of Cannabis sativa associated with archaeological human remains from China. Ribosomal and Cannabis specific chloroplast DNA regions were PCR amplified. Sequencing of a species-specific region and subsequent comparison with published sequences were performed. Successful amplification, sequencing and sequence comparison with published data suggested the presence of hemp specific DNA in the archeological specimen. The role of Humulus japonicus Sieb. et Zucc. in the evolution of Cannabis is also indicated. The identification of ancient DNA of 2500 years old C. sativa sample showed that C. sativa races might have been introduced into China from the European–Siberian center of diversity.     

A Tal-Ph<Superscript>I</Superscript> wheat genetic stock facilitates efficient alien introgression

The genetic stock Chinese Spring Ph^I (refer as CS-Ph^I hereafter) with the Ph ^I gene (Ph gene inhibitor, introduced from a high-pairing accession of Aegilops speltoides) was crossed as a male parent to a Tai-gu genic male-sterile wheat with the Tal gene and backcrossed once to CS-Ph^I to develop the Tal-Ph^I genetic stock. The Tal-Ph^I stock, CS-Ph^I as well as Chinese Spring (CS), were test-crossed using Aegilops peregrina (syn. Aegilops variabilis) to test the effectiveness of the Ph ^I gene inducing homoeologous chromosome pairing in the Tal-Ph^I stock. At meiotic I(MI) of pollen mother cells (PMCs), the average chromosome pairing of the TC₁ testcrosses of TalCSPh^IC_08–4/Ae. peregrina, TalCSPh^IC_11–5/Ae. peregrina and CS/Ae. peregrina was 26.81 I + 3.64 II + 0.33  + 0.07 III + 0.01 IV, 24.75 I + 4.58 II + 0.25  + 0.21 III + 0.07 IV and 32.25 I + 1.38 II, respectively. These data indicated that the Ph ^I gene could promote homoeologous chromosome pairing in the Tai-gu male sterile background. In order to verify the introgression of the chromatin from Ae. speltoides into CS in the three CS-Ph^I lines, a total of 79 SSR primers located on group-3 chromosomes were used for PCR analysis using the genomic DNA of CS, Ae. speltoides and the three CS-Ph^I lines. Two markers Xwmc505 _-110 and Xwmc674 _-160 amplified S genome-specific fragments from Ae. speltoides in lines Ph^IC_04–13 and Ph^IC_11–5, providing molecular evidence for the introgression of Ae. speltoides-specific chromatin in the two lines. Furthermore, some 3D-specifc SSR markers were missing in line Ph^IC_04–13, indicating there might be a deletion of chromosome 3D in this line. In further experiments, a BC₁ population was produced from the cross of Tal-Ph^I/Triticum durum-Dasypyrum villosum amphiploid (AABBVV)//CS-Ph^I, and the progenies were further screened for chromosome recombination by GISH analysis. A homozygous translocation line T5VS·5VL-5DL was identified from the BC₁F₂ by genomic in situ hybridization, C-banding and SSR analysis. The results of the present study demonstrate the Tal-Ph^I is a useful genetic stock for transferring alien genes into common wheat.     

Thermal,swelling and stability kinetics of chitosan based semi-interpenetrating network hydrogels

The present study is focused on studying the swelling kinetics, thermal and aqueous stabilities, and determination of various forms of water in the chitosan (CS) and polyacrylonitrile (PAN) blend and semi-interpenetrating polymer network (sIPN). CS/PAN blend hydrogel films were prepared by solution casting technique. The blend film with optimum swelling properties was selected for the synthesis of sIPN. CS in the blend was crosslinked with the vapors of Glutaraldehyde (GTA) to prepare sIPN. The fabricated CS/PAN blend and sIPN hydrogels films were characterized with Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and field emission scanning electron microscope (FESEM). The kinetics of swelling, bound and unbound waters and aqueous stability were determined experimentally. FESEM showed good miscibility between CS and PAN, FTIR showed no chemical interaction between CS and PAN; however, it did show a doublet for the sIPN, TGA showed improved thermal stability and swelling kinetic followed second order kinetics. The degree of swelling of the sIPN hydrogels samples at room temperature varied from ~2200 % (with a fair degree of stability (~30 %)) to ~1000 % (with high degree of aqueous stability (43 %)) with increase in the crosslinking time. The calculated unbound water (W_UB) max., for the blend was 52.3 % whereas for the bound (W_B) the max., was 41.9 %. However, for sIPN hydrogel films, the W_UB water decreased (max. 21.0 %) where as the W_B increased (max. 52.0 %). The decrease in W_UB and increase in the W_B is attributed to the formation of a compact structure and increase in the contact area between the water and polymers in sIPN hydrogels due to the induction of new water contacting point in these hydrogel films, respectively.