Importance of Limestone Specific Surface for Assessing Neutralization Effectiveness in Soilless Root Substrate

The relationship of specific surface to particle diameter and calcium carbonate (CaCO₃) content of limestone was examined. Limestones obtained from 20 North American quarries were wet sieved into eight particle diameter fractions (600 to ?38 µm). Specific surface of particles was measured in each fraction following the Brunauer-Emmett-Teller theory. The range in specific surface across the 20 sources varied from 74-fold in the coarsest particles (600–300 µm) to 20-fold in the finest particles (?38 µm). The pattern of specific surface progressing from the coarsest to the finest particles varied radically between sources. The relationship between specific surface and CaCO₃ content was likewise very weak. While particle diameter and CaCO₃ equivalent remain the traditional measurements for defining limestone for field production, specific surface provides additional information valuable to define the stricter neutralization capacities of limestone for soilless root substrates.     

Molecular characterisation and diagnostics of some Longidorus species (Nematoda: Longidoridae) from Russia and other countries using rRNA genes

The needle nematodes of the genus Longidorus can cause diseases of various crops and trees, and are comprised of more than 150 valid species. Eleven valid and six unidentified species of the genus Longidorus collected in different regions of Russia, two states of USA, Germany, New Zealand and Ukraine were molecularly characterized using analysis of the partial 18S rRNA and the D2–D3 expansion segments of the 28S rRNA gene sequences. Fifty-four partial 28S rRNA and fifteen partial 18S rRNA gene sequences were obtained for the present study. Using molecular criteria, we confirmed the morphological identification and distinguished between the following species: L. aetnaeus, L. africanus, L. andalusicus, L. artemisiae, L. caespiticola, L. distinctus, L. elongatus, L. euonymus, L. intermedius, L. leptocephalus and L. lignosus. Two longidorid populations from Russia and four from California were not identified to a species level. We obtained the full length D2–D3 of 28S rRNA gene sequence from several freshly-collected L. artemisiae samples. We confirmed the identity of the D2 region of 28S rRNA gene sequence with a short D2 of 28S rRNA gene fragment sequence previously obtained from formalin-fixed nematodes embedded in the L. artemisiae paratype slides. Longidorus lignosus was molecularly characterized and L. aetnaeus was reported from Russia for the first time. PCR-D2-D3-RFLP diagnostic profiles generated by five restriction enzymes: AluI, HinfI, Bsp143I, Tru1I and RsaI are presented for sixteen Longidorus species.     

Trace mineral source impacts rumen trace mineral metabolism and fiber digestion in steers fed a medium-quality grass hay diet

Twelve Angus steers (BW 452.8 ± 6.1 kg) fitted with ruminal cannulae were used to determine the impact of trace mineral (TM) source on digestibility, ruminal volatile fatty acid (VFA) composition, ruminal soluble concentrations of Cu, Zn, and Mn, and relative binding strength of trace minerals located in the rumen insoluble digesta fraction. Steers were fed a medium-quality grass hay diet (DM basis: 10.8% CP, 63.1% neutral detergent fiber [NDF], 6.9 mg Cu/kg, 65.5 mg Mn/kg, and 39.4 mg Zn/kg) supplemented with protein for 21 d. Treatments consisted of either sulfate (STM) or hydroxy (HTM) sources (n = 6 steers/treatment) to provide 20, 40, and 60 mg supplemental Cu, Mn, and Zn/kg DM, respectively. Following a 21-d adaptation period, total fecal output was collected for 5 d. Dry matter (P < 0.07) and CP (P < 0.06) digestibility tended to be reduced, and NDF (P < 0.04) and acid detergent fiber (ADF) (P < 0.05) digestibility were reduced in STM- vs. HTM-supplemented steers. On day 6, ruminal fluid was collected at 0, 2, and 4 h post-feeding and analyzed for VFA. There were no treatment x time interactions for VFA. Steers receiving HTM had less (P < 0.02) molar proportions of butyric acid and greater (P < 0.05) total VFA concentrations than STM-supplemented steers. Steers were then fed the same diet without supplemental Cu, Zn, or Mn for 14 d. On day 15 steers received a pulse dose of 20 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either STM or HTM (n = 6 steers/treatment). Ruminal samples were obtained at 2-h intervals starting at −4 and ending at 24 h relative to dosing. There was a treatment x time interaction (P < 0.03) for ruminal soluble Cu, Mn, and Zn concentrations. Ruminal soluble mineral concentrations were greater (P < 0.05) for Cu at 4, 6, 8, 10, 12, and 14 h; for Mn at 4 and 6 h; and for Zn at 4, 6, and 8 h post-dosing in STM compared with HTM-supplemented steers. Copper concentrations were greater (P < 0.05) at 12 and 24 h and Zn concentrations in ruminal solid digesta were greater at 24 h in HTM-supplemented steers. Upon dialysis against Tris-EDTA, the percent Zn released from digesta was greater (P < 0.05) at 12 h (P < 0.03) and 24 h (P < 0.05), and the percent Cu released was greater (P < 0.02) at 24 h post-dosing in HTM steers when compared with STM-supplemented steers. Results indicate that Cu and Zn from HTM have low solubility in the rumen and appear to be less tightly bound to ruminal solid digesta than Cu and Zn from STM. The lower ruminal soluble concentrations of Cu and Zn in steers given HTM were associated with greater fiber digestibility.     

Evaluating water stress in irrigated olives: correlation of soil water status,tree water status,and thermal imagery

Irrigation of olive orchards is challenged to optimize both yields and oil quality. Best management practices for olive irrigation will likely depend on the ability to maintain mild to moderate levels of water stress during at least some parts of the growing season. We examined a number of soil, plant and remote sensing parameters for evaluating water stress in bearing olive (var. Barnea) trees in Israel. The trees were irrigated with five water application treatments (30, 50, 75, 100 and 125% of potential evapotranspiration) and the measurements of soil water content and potential, mid-day stem water potential, and stomatal resistance were taken. Remote thermal images of individual trees were used to alternatively measure average canopy temperature and to calculate the tree’s crop water stress index (CWSI), testing empirical and analytical approaches. A strong non-linear response showing similar trends and behavior was evident in soil and plant water status measurements as well as in the CWSI, with decreasing rates of change at the higher irrigation application levels. No statistically significant difference was found between the analytical and the empirical CWSI, suggesting that the relative simplicity of the analytical method would make it preferable in practical applications.     

Exploration of AgNW/PU nanoweb as ECG textile electrodes and comparison with Ag/AgCl electrodes

This study aims to measure ECG signals by the AgNW/PU nanoweb electrodes, and, to compare with signals measured by the conventional Ag/AgCl electrodes. Finally, to investigate the usage potential of the AgNW/PU nanoweb as ECG textile electrodes. The ECG textile electrodes were fabricated, using the polyurethane (PU) nanoweb (Pardam, s.r.o., Czech Republic) coated with 1 wt% of silver nanowires (AgNW) dispersed in ethanol (KLK Co., Korea). To measure the ECG signals, eight participants (Male:Female=1:1) were collected, and then, the signals were measured at rest-state and stress-state in anechoic chamber using Lead I method. From the measured ECG signals, heart rate (HR) and R-R intervals were acquired by using MP150 (Biopac system Inc., USA) and Acqknowledge (ver. 4.2, Biopac system Inc., USA), and then, analyzed by using Kubios HRV (ver. 2.0., Biosignal Analysis and Medical Imaging Group, Finland). To examine the morphology of the signals, direct visual evaluation was performed. Also, to statistically compare to the signals, Wilcoxon signed-rank test was conducted by using R statistical language and RStudio (1.0.143 ver., RStudio, Inc., USA). As a result, the ECG waveforms measured by the two different types of electrodes looked similar, especially, QRS-complex, P-wave and T-wave as well as R-peaks properly appeared. Also, there was not a significant difference of HR and RR-intervals measured by the two different types of electrodes. It demonstrated that the new AgNW/PU nanoweb electrodes could perform properly as ECG electrodes.     

Atlantic herring as a dietary component for culture of Atlantic salmon

Chopped herring was readily eaten by Atlantic salmon. Fry, parr and smolts grew well on a herring-rich diet but after long periods fry and smolts developed symptoms of nutritional deficiency which were quickly cured by omitting herring from the diet. Parr, fed herring and liver separately on alternate days, did not show ill effects. The symptoms are believed due to a high content of thiaminase in herring. Mixing herring with other thiamine-rich foods did not prevent the harmful effects in salmon, pre-sumably owing to inactivation of the thiamine in the food mixture. It is suggested that the beneficial effects of a herring diet can be retained and the harmful effects prevented by feeding herring and some other thiaminase-free food separately during alternate periods.     

A case study in conservation politics: California's coastline initiative

The people of the State of California (USA) have voted to put coastline development under strict State control; control had previously been vested in local communities, in so far as it had existed at all. The newly-established policy represents a major break with tradition, as government authority over zoning and other development control has previously always been vested in the local community. It also represents a major break with the American tradition of unguided growth and development, for scenic and recreational values were considered more important by the majority of voters. Analysis of voting patterns shows that the strongest support was found among urbanites without much coastal access, while the strongest opposition was found in rural coastal counties (which stand to lose money) and rural mountain counties (where developers fear the mountains may be regulated next).     

MicroRNA expression in zebrafish embryonic development

MicroRNAs (miRNAs) are small noncoding RNAs, about 21 nucleotides in length, that can regulate gene expression by base-pairing to partially complementary mRNAs. Regulation by miRNAs can play essential roles in embryonic development. We determined the temporal and spatial expression patterns of 115 conserved vertebrate miRNAs in zebrafish embryos by microarrays and by in situ hybridizations, using locked-nucleic acid-modified oligonucleotide probes. Most miRNAs were expressed in a highly tissue-specific manner during segmentation and later stages, but not early in development, which suggests that their role is not in tissue fate establishment but in differentiation or maintenance of tissue identity.