Anaerobic treatment of low-strength municipal wastewater by a two-stage pilot plant under psychrophilic conditions

A two-stage anaerobic treatment pilot plant was tested for the treatment of raw domestic wastewater under temperatures ranging from 21 to 14 degrees C. The plant consisted of a hydrolytic upflow sludge bed (HUSB) digester (25.5m3) followed by an upflow anaerobic sludge blanket (UASB) digester (20.36m3). The hydraulic retention time (HRT) varied from 5.7 to 2.8h for the first stage (HUSB digester) and from 13.9 to 6.5h for the second stage (UASB digester). Total suspended solids (TSS), total chemical oxygen demand (TCOD), and biochemical oxygen demand (BOD) removals ranged from 76% to 89%, from 49% to 65%, and from 50% to 77%, respectively, for the overall system. The percentage of influent COD converted to methane was 36.1%, the hydrolysis of influent volatile suspended solids (VSS) reached 59.7% and excess biomass was 21.6% of the incoming VSS. Plant performance was influenced by the wastewater concentration and temperature, yet better results were obtained for influent COD higher than 250mg/l.     

Intracellular Ca2+ transients in mouse soleus muscle after hindlimb unloading and reloading.

The objective of this study was to determine whether altered intracellular Ca(2+) handling contributes to the specific force loss in the soleus muscle after unloading and/or subsequent reloading of mouse hindlimbs. Three groups of female ICR mice were studied: 1) unloaded mice (n = 11) that were hindlimb suspended for 14 days, 2) reloaded mice (n = 10) that were returned to their cages for 1 day after 14 days of hindlimb suspension, and 3) control mice (n = 10) that had normal cage activity. Maximum isometric tetanic force (P(o)) was determined in the soleus muscle from the left hindlimb, and resting free cytosolic Ca(2+) concentration ([Ca(2+)](i)), tetanic [Ca(2+)](i), and 4-chloro-m-cresol-induced [Ca(2+)](i) were measured in the contralateral soleus muscle by confocal laser scanning microscopy. Unloading and reloading increased resting [Ca(2+)](i) above control by 36% and 24%, respectively. Although unloading reduced P(o) and specific force by 58% and 24%, respectively, compared with control mice, there was no difference in tetanic [Ca(2+)](i). P(o), specific force, and tetanic [Ca(2+)](i) were reduced by 58%, 23%, and 23%, respectively, in the reloaded animals compared with control mice; however, tetanic [Ca(2+)](i) was not different between unloaded and reloaded mice. These data indicate that although hindlimb suspension results in disturbed intracellular Ca(2+) homeostasis, changes in tetanic [Ca(2+)](i) do not contribute to force deficits. Compared with unloading, 24 h of physiological reloading in the mouse do not result in further changes in maximal strength or tetanic [Ca(2+)](i).     

Peptidomimetic fluoromethylketone rescues mice from lethal endotoxic shock.

BACKGROUND: Septic shock is a leading cause of mortality in intensive care units. No new interventions in the last 20 years have made a substantial impact on the outcome of patients with septic shock. Identification of inhibitable pathways that mediate death in shock is an important goal. MATERIALS AND METHODS: Two novel caspase inhibitors, (2-indolyl)-carbonyl-Ala-Asp-fluoromethylketone (IDN 1529) and (1-methyl-3-methyl-2-indolyl)-carbonyl-Val-Asp-fluoromethylketone (IDN 1965), were studied in a murine model of endotoxic shock. RESULTS: IDN 1529 prolonged survival when given before or up to 3 hr after high-dose LPS (p < 0.01) and increased by 2.2-fold the number of animals surviving longterm after a lower dose of LPS (p < 0.01). Despite its similar chemical structure, IDN 1965 lacked these protective effects. Both compounds inhibited caspases 1, 2, 3, 6, 8, and 9, and both afforded comparable reduction in Fas- and LPS-induced caspase 3-like activity and apoptosis. Paradoxically, administration of IDN 1529 but not IDN 1965 led to an increase in the LPS-induced elevation of serum cytokines related directly (IL-1beta, IL-18) or indirectly (IL-1alpha, IL-1Ra) to the action of caspase 1. CONCLUSIONS: A process that appears to be distinct from both apoptosis and the release of inflammatory cytokines is a late-acting requirement for lethality in endotoxic shock. Inhibition of this process can rescue mice even when therapy is initiated after LPS has made the mice severely ill.     

Movements of adult Atlantic salmon in relation to a hydroelectric dam and fish ladder

The movements of adult Atlantic salmon were recorded as they approached, entered and ascended the pool-and-orifice fish ladder at Pitlochry Dam, Scotland. Thirty-nine returning salmon were captured in the River Tummel by rod-and-line angling, radio-tagged and released near where they were caught. The subsequent movements of each fish were then monitored. An electronic fish counter collected additional data on movements of untagged fish past a fixed point in the ladder. Of the 39 fish that were radio-tagged, 29 individuals were recorded approaching and ascended the ladder. The remaining fish either did not approach the dam (three fish), approached the dam after detailed tracking had ended (two fish), were recaptured by anglers (three fish), or the radio tags failed (two fish). Salmon released earlier in the year delayed longer before first approaching the dam. Delays between first approaching the dam and ascent of the ladder were greater for fish that approached the dam earlier. The majority of salmon visited the ladder entrance more than once (maximum 10 visits) before ascending. Having entered, all but four salmon ascended the fish ladder successfully on their first attempt. The four individuals that failed to do so succeeded on their second attempt. The rate at which salmon ascended the ladder was related directly to temperature. The shortest ascent time of a radio-tagged salmon was 5·25 h. Movements of eight of 11 tagged fish through the ladder ceased with the onset of darkness but continued on the following morning. No radio-tagged fish entered the ladder at temperatures below 9) C. Similarly, few untagged fish were recorded ascending the ladder by the electronic fish counter at water temperatures below 8·5) C. Records from the fish counter indicated that 92% of upstream movements were made during daylight.     

Evaluation of a closed system,diffusive and humidity-induced convective throughflow ventilation on the growth and physiology of cauliflower in vitro

The effects of ethylene inhibitors (silver nitrate – AgNO₃ and silver thiosulphate – Ag₂S₂O₃ as inhibitors of ethylene activity, cobalt chloride – CoCl₂ as inhibitor of ethylene biosynthesis) and ethylene stimulator (aminocyclopropane-1-carboxylic acid – ACC) were studied on the growth of cauliflower (Brassica oleracea L.) seedlings cultured in closed vessels (60 cm³). The addition of ethylene inhibitors have significant stimulatory effects on the growth and development of seedlings and the effects were greatest with 10 μM AgNO₃, the fresh weight of leaves was 2.6×, and the leaf area 2.8× those of the control (no additives). The effects of various methods of ventilation (humidity-induced convective through-flow ventilation, diffusive ventilation and sealed condition) on the growth and physiology of in vitrocauliflower seedlings were also investigated. The seedlings were cultured either in the presence or absence of AgNO₃ (inhibitors of ethylene activity) and ACC (a precursor). Ethylene and CO₂ levels in the head-space of the culture vessels were monitored. The humidity-induced through-flow ventilation system has shown to be effective for improving growth, leaf chlorophyll content and the rate of net photosynthesis and preventing symptoms of hyperhydricity, such as leaf epinasty, and franginess, reduction of leaf area etc. In contrast, the results also indicated that the sealing of culture vessels could have serious inhibitory effects on growth and development, induce hyperhydricity and reduce leaf chlorophyll content. In the light period, CO₂ depletion occurred in the head-space of the sealed vessels (ca. 40 μl l^-1), the CO₂ concentration increased with increasing efficiency of the ventilation. No ethylene accumulation was noticed in the head-space of the culture vessels when humidity-induced throughflow ventilation was applied; however, high ethylene accumulation occurred in sealed vessels. This revised version was published online in June 2006 with corrections to the Cover Date.     

The cardiac neural crest in Ambystoma mexicanum.

To establish whether a region of the cranial neural crest contributes cells to the developing heart of Ambystoma mexicanum (axolotl), as it does in many other vertebrates, we constructed a fate map for the neural crest in late neurula stage (stage 19-20) embryos. The fluorescent vital dye, Dil, was used as the lineage label. The various regions of the cranial neural folds were identified in relation to such landmarks as the developing forebrain, midbrain and hindbrain, and the appearance and extent of emerging somites. Labelled cells originating in the rhombencephalic region were found in the aortic arches and in the truncus arteriosus, and occasionally in the walls of the conus arteriosus. Cells were also found in the third and fourth branchial arches. Labelled neural crest from the adjacent anterior trunk region appeared neither in the heart nor the visceral skeleton, whereas those from the mesencephalic region contributed to the first hypobranchial cartilage and to the first three branchial arches, but not to the heart. No labelled cells from any of the regions were seen in the ventricle or auricle.     

Regioselective acylation of several polyhydroxylated natural compounds by Candida antarctica lipase B

Regioselective acylation of four polyhydroxylated natural compounds, deacetyl asperulosidic acid (1), asperulosidic acid (2), puerarin (3) and resveratrol (4) by Candida antarctica Lipase B in the presence of various acyl donors (vinyl acetate, vinyl decanoate or vinyl cinnamoate) was studied. Compounds 1, 2 and 4 were regioselectively acetylated with vinyl acetate to afford products, 3'-O-acetyl-10-O-deacetylasperulosidic acid (1a), 3',6'-O-diacetyl-10-O-deacetylasperulosidic acid (1b), 3'-O-acetylasperulosidic acid (2a), 3',6'-O-diacetylasperulosidic acid (2b), 4'-O-acetylresveratrol (4a), respectively, with yields of 22 to 50%, while reactions with vinyl decanoate and vinyl cinnamoate were slow with lower yields. Compound 3 was readily acylated with all three acyl donors and quantitatively converted to products 6'-O-acetylpuerarin (3a), 6'-O-decanoylpuerarin (3b), 6'-O-cinnamoylpuerarin (3c), respectively. The structures of these acylated products were determined by spectroscopic methods (MS and NMR).     

Evidence that 3-phosphoinositide-dependent protein kinase-1 mediates phosphorylation of p70 S6 kinase in vivo at Thr-412 as well as Thr-252

Protein kinase B and p70 S6 kinase are members of the cyclic AMP-dependent/cyclic GMP-dependent/protein kinase C subfamily of protein kinases and are activated by a phosphatidylinositol 3-kinase-dependent pathway when cells are stimulated with insulin or growth factors. Both of these kinases are activated in cells by phosphorylation of a conserved residue in the kinase domain (Thr-308 of protein kinase B (PKB) and Thr-252 of p70 S6 kinase) and another conserved residue located C-terminal to the kinase domain (Ser-473 of PKB and Thr-412 of p70 S6 kinase). Thr-308 of PKBalpha and Thr-252 of p70 S6 kinase are phosphorylated by 3-phosphoinositide-dependent protein kinase-1 (PDK1) in vitro. Recent work has shown that PDK1 interacts with a region of protein kinase C-related kinase-2, termed the PDK1 interacting fragment (PIF). Interaction with PIF converts PDK1 from a form that phosphorylates PKB at Thr-308 alone to a species capable of phosphorylating Ser-473 as well as Thr-308. This suggests that PDK1 may be the enzyme that phosphorylates both residues in vivo. Here we demonstrate that PDK1 is capable of phosphorylating p70 S6 kinase at Thr-412 in vitro. We study the effect of PIF on the ability of PDK1 to phosphorylate p70 S6 kinase. Surprisingly, we find that PDK1 bound to PIF is no longer able to interact with or phosphorylate p70 S6 kinase in vitro at either Thr-252 or Thr-412. The expression of PIF in cells prevents insulin-like growth factor 1 from inducing the activation of the p70 S6 kinase and its phosphorylation at Thr-412. Overexpression of PDK1 in cells induces the phosphorylation of p70 S6 kinase at Thr-412 in unstimulated cells, and a catalytically inactive mutant of PDK1 prevents the phosphorylation of p70 S6K at Thr-412 in insulin-like growth factor 1-stimulated cells. These observations indicate that PDK1 regulates the activation of p70 S6 kinase and provides evidence that PDK1 mediates the phosphorylation of p70 S6 kinase at Thr-412.     

Selection of antibiotic-resistant standard plate count bacteria during water treatment.

Standard plate count (SPC) bacteria were isolated from a drinking-water treatment facility and from the river supplying the facility. All isolates were identified and tested for their resistance to six antibiotics to determine if drug-resistant bacteria were selected for as a consequence of water treatment. Among the isolates surviving our test procedures, there was a significant selection (P less than 0.05) of gram-negative SPC organisms resistant to two or more of the test antibiotics. These bacteria were isolated from the flash mix tank, where chlorine, alum, and lime are added to the water. Streptomycin resistance in particular was more frequent in this population as compared with bacteria in the untreated river water (P less than 0.01). SPC bacteria from the clear well, which is a tank holding the finished drinking water at the treatment facility, were also more frequently antibiotic resistant than were the respective river water populations. When 15.8 and 18.2% of the river water bacteria were multiply antibiotic resistant, 57.1 and 43.5%, respectively, of the SPC bacteria in the clear well were multiply antibiotic resistant. Selection for bacteria exhibiting resistance to streptomycin was achieved by chlorinating river water in the laboratory. We concluded that the selective factors operating in the aquatic environment of a water treatment facility can act to increase the proportion of antibiotic-resistant members of the SPC bacterial population in treated drinking water.