Effect of suplemental nitrogen source and feeding frequency on nutrient supply to lambs fed a kikuyu grass (Pennisetum clandestinum) hay-based diet

Eight castrated male lambs (35 ± 4 kg live weight), fed a basal diet of kikuyu grass hay, were used in a replicated 4 × 4 Latin Square experiment with a 2 × 2 factorial arrangement of treatments to evaluate the effect of supplemental feeding frequency and source of rumen degradable N on intake, digestibility, ruminal fermentation, and microbial protein yield. Treatments were supplementation with cassava meal plus calcium caseinate or cassava meal plus urea offered at a rate of 7 g/kg live weight daily in one or two meals per day. Lambs were fed twice daily in such manner to allow ad libitum comsumption of forage. There was significant feeding frequency by N source interaction on variables of intake. In general, intake of feed components was higher (P ≤ 0.05) by lambs offered the caseinate-supplement twice daily over intake observed in lambs given the others diet treatments. Digestibility of feed components was neither affected by supplemental N source (DM, P = 0.541; OM, P = 0.585; NDF, P = 0.828) nor by feeding frequency (DM, P = 0.122; OM, P = 0.175; NDF, P = 0.591). Urinary excretion of N increased (P ≤ 0.05) in lambs supplemented twice daily whereas N retention was similar for all treatments (N source, P = 0.748; feeding frequency, P = 0.418). Microbial protein entering into the small intestine was affected by the interaction between feeding frequency and N source such as an increasing (P < 0.10) in this variable was observed when lambs received the caseinate but not the urea supplement twice daily. Efficiency of microbial protein synthesis, however, was not affected by treatments (N source, P = 0.588; feeding frequency, P = 0.334). Rumen pH averaged 6.70 and it was neither affected by N source (P = 0.827) nor by feeding frequency (P = 0.740). Ruminal concentration of ammonia N was not affected by feeding frequency (P = 0.144) while it increased (P < 0.05) when urea rather than caseinate was the supplemental N source (mean of 7.61 mg/dl vs. 6.00 mg/dl). Concentration of sugars in rumen fluid was higher (P ≤ 0.05) in lambs supplemented once a day compared to twice daily (mean of 49.4 mg/dl vs. 34.4 mg/dl) for both N sources. A significant (P ≤ 0.05) N source by feeding frequency interaction effect was observed for ruminal concentrations of α-amino N compounds. In urea treatment α-amino N concentration increased (P ≤ 0.05) in lambs receiving the supplement twice daily compared to once a day (mean of 4.59 mg/dl vs. 3.70 mg/dl) while in caseinate treatment it was higher (P ≤ 0.05) in lambs offered the supplement in one meal per day compared to twice daily (mean of 5.29 mg/dl vs. 4.07 mg/dl). In conclusion, for ruminants fed a tropical grass-based diet, starch-rich supplement containing non-protein N as N source may be offered only once a day whereas the supply of nutrients may be improved if degradable true protein is included as N source and supplement is offered in two meals per day.     

Monitoring of aquatic macroinvertebrates as bioindicator for assessing the health of wetlands: A case study in the Central Himalayas,India

The present contribution encompasses the first case study on the aquatic macroinvertebrates as bioindicators for assessing the health of Asan wetland (area 3.2 km²), located in the foothills of Central Himalayas, India. Monthly sampling from all the sampling sites in five replicates was made for a period of 12 months (July 2002–June 2003) at 9:00–11:00 h. A total of 32 species of macroinvertebrates were found with the Ephemeroptera and Gastropoda being the most abundant component of invertebrates communities. The Shannon–Wiener diversity index calculated for macroinvertebrates ranged from 3.50 to 4.61. Seasonal fluctuations in the density of macroinvertebrates revealed maximum density (451–503 ind m^?2) during winter and minimum (126–143 ind m^?2) during monsoon season. The density of macroinvertebrates was influenced by the anthropogenic disturbances and water level fluctuations causing disturbance in the littoral zone of the wetland. The statistical relationships between turbidity, transparency, dissolved oxygen and water temperature and macroinvertebrates of Asan wetland were also computed for assessing the impact of anthropogenic disturbances on macroinvertebrates.     

Comparative efficacy of different approaches to managing Meloidogyne incognita on green bean

A greenhouse study was conducted to compare the relative efficacy of different approaches to managing Meloidogyne incognita on green bean. These approaches included chemical (fumigant, non-fumigant, seed dressing, and seed dip), biological (the egg-parasitic fungus, Paecilomyces lilacinus and the mycorrhizal fungus Glomus sp.), physical (soil solarization), and cultural (chicken litter and urea) methods. Accordingly, nine different control materials and application methods plus nematode-infected and non-infected controls were compared. Two important parameters were considered: plant response (plant growth and root galling) and nematode reproduction (production of eggs and the reproduction factor Rf). The results showed that the use of chicken litter as an organic fertilizer severely affected the growth and survival of the plants. Therefore, this treatment was removed from the evaluation test. All of the other eight treatments were found to be effective against nematode reproduction, but with different levels of efficacy. The eight treatments decreased (38.9–99.8%) root galling, increased plant growth and suppressed nematode reproduction. Based on three important criteria, namely, gall index (GI), egg mass index (EMI), and nematode reproduction factor (RF), the tested materials and methods were categorized into three groups according to their relative control efficacy under the applied test conditions. The three groups were as follows: (1) the relatively high effective group (GI = 1.0–1.4, Rf = 0.07–0.01), which included the fumigant dazomet, the non-fumigant fenamiphos, soil solarization, and seed dip with fenamiphos; (2) the relatively moderate effective group (GI = 3.4–4.0, Rf = 0.24–0.60), which included seed dressing with fenamiphos and urea; and (3) the relatively less effective group (GI = 5.0, Rf = 32.2–37.2), which included P. lilacinus and Glomus sp.     

Microbial community in conventional and extended aeration activated sludge plants in India

This study was conducted to determine the relationship between the ciliated protozoan population density and the effluent quality at two different modes of activated sludge plants (ASP) operating in India. A wide variety of ciliated protozoa (26 sp.) in higher density were identified at the conventional ASP, Haridwar, that delivered high quality effluent in terms of low biochemical oxygen demand (BOD = 15 mg/L), suspended solids (SS = 17 mg/L), turbidity (2.7 NTU), ammoniacal nitrogen (NH₃–N = 3 mg/L), chemical oxygen demand (COD = 37 mg/L), total coliforms (TC = log 5.2), fecal coliforms (FC = log 4.7) and fecal Streptococci (FS = log 3.7). Whereas, a few protozoan species (15 sp.) in lower density were reported in extended aeration plant (EAP) Delhi, that delivered turbid and lower quality effluent in terms of high BOD (23 mg/L), SS (80 mg/L), turbidity (12 NTU), NH₃–N (55 mg/L) and COD (68 mg/L). However, in spite of relatively poor effluent quality, lower concentration of TC (log 4.2), FC (log 3.9) and FS (log 3.2) was observed in EAP, Delhi. The constant presence of two filamentous bacterial species (Beggiatoa and Spirillum) in extended aeration process can be considered as the probable reason of high coliforms removal, since filamentous bacteria are capable of removing organic as well as microbial pollutants from wastewater.     

Evaluation of a two-stage in vitro technique for estimating digestibility of equine feeds using horse faeces as the source of microbial inoculum

To develop a two-stage in vitro technique that simulates both pre-caecal and hind gut digestion processes, four enzymatic pre-digestion treatments by pepsin and α-amylase (ET0 = control, ET1 = 2 h pepsin + 2 h amylase, ET2 = 2 h pepsin + 4 h amylase, ET3 = 8 h pepsin + 16 h amylase) were tested on oat hay (OH), barley grain (BG) and soybean meal (SBM). Investigated parameters were enzymatic organic matter digestibility (OMDe), and gas production (G48h, G72h) and OM digestibility (OMD) using horse faeces as a source of microbial inoculum.Enzymatic pre-digestion treatments affected (P<0.05) investigated parameters and their ranking differed among feeds. Only OMD of BG and SBM were higher after the pre-digestion treatment. OMD prior to (ET0) and after ET3 application were, successively, 0.357 versus 0.351 (OH), 0.71 versus 0.79 (BG) and 0.70 versus 0.78 (SBM). Net gas production overestimated fermentation potential of non-pre-digested feeds. G72h (ml/g DM) prior to (ET0) and after ET3 application were, successively, 80.3 versus 58.0 (OH), 151.7 versus 30.4 (BG) and 110.6 versus 37.7 (SBM).It was concluded that the enzymatic pre-digestion treatments effects varied among tested feeds, and that the suggested procedure be extended and validated with a large array of feeds of known digestibility values.     

Effects of exposing pigs to moving and odors in a simulated slaughter chute

Pigs in the finishing stage are infrequently handled and can be difficult to handle when experiencing novel situations. This study sought to determine the effects of minimal training and a novel odor/taste reward on the ease of handling finishing pigs in a novel environment. Pigs were assigned to one of four treatments organized in a factorial arrangement: training and odor exposure at the barn or not (trained or non-trained, respectively) and provision or not of maple syrup in the simulated pre-stun area of a slaughter plant (reward or no reward, respectively). Trained pigs (n = 14 pens) were let out of their home pens and onto a trailer for 10 min/d for 10 d and could chew on maple syrup-soaked flags. Non-trained pigs (n = 14 pens) were not handled or exposed to maple syrup. After the 10 d, trained and non-trained pigs were transported, unloaded and then experienced a novel simulated pre-stun area. A maple syrup-soaked flag (reward) was dragged through the simulated pre-stun area and put in a simulated CO₂ stun box. Non-rewarded pigs were not exposed to maple syrup. Trained pigs unloaded the trailer and reached the resting pen faster (P = 0.014) than non-trained pigs. Trained pigs had fewer (P = 0.02) blood neutrophils and more (P = 0.03) lymphocytes than non-trained pigs. Rewarded pigs received fewer (P = 0.02) taps before reaching the simulated CO₂ stun box than non-rewarded pigs. Cortisol concentration increased (P = 0.004) when the total time to reach the simulated CO₂ stun box increased. Pigs that were allowed to exercise out of their home pen and were given access to an odor/taste reward moved faster and the neutrophil:lymphocyte ratio was decreased when exposed to a novel environment containing the same odor/taste reward.     

Effects of plant diversity on biomass production and substrate nitrogen in a subsurface vertical flow constructed wetland

Most biodiversity experiments have been conducted in grassland ecosystems with nitrogen limitation, while little research has been conducted on relationships between plant biomass production, substrate nitrogen retention and plant diversity in wetlands with continuous nitrogen supply. We conducted a plant diversity experiment in a subsurface vertical flow constructed wetland for treating domestic wastewater in southeastern China. Plant aboveground biomass production ranged from 20 to 3121 g m^?2 yr^?1 across all plant communities. In general, plant biomass production was positively correlated with species richness (P = 0.001) and functional group richness (P = 0.001). Substrate nitrate concentration increased significantly with increasing plant species richness (P = 0.046), but not with functional group richness (P = 0.550). Furthermore, legumes did not affect biomass production (P = 0.255), retention of substrate nitrate (P = 0.280) and ammonium (P = 0.269). Compared to the most productive of the corresponding monocultures, transgressive overyielding of mixed plant communities did not occur in most polycultures. Because greater diversity of plant community led to higher biomass production and substrate nitrogen retention, thus we recommend that plant biodiversity should be incorporated in constructed wetlands to improve wastewater treatment efficiency.     

Effect of grazing and homeopathy on milk production and immunity of Merino derived ewes

The effect of grazing and homeopathic therapy on sheep immune response and milk production was investigated on 40 multiparous Merino derived ewes. Twenty animals were housed in an indoor-bedded pen (P), whereas 20 others were allowed to graze on pasture for 9 h/d (G). P and G animals were fed an equivalent diet in terms of dry matter intake, crude protein percentage and energy concentration. In each group, 10 animals were subjected to unicistic homeopathic treatments (H), while 10 ewes were kept as a control and treated with conventional medicine when necessary (C). The grazing rearing system had a marked positive effect on in vivo cellular immune response (delayed-type hypersensivity to PHA, P < 0.001). Grazing animals produced more milk than the penned ones (1048.00 ± 75.61 kg versus 853.04 ± 67.78 kg, P < 0.05), with increased content of milk fat (7.69 ± 0.15% versus 7.25 ± 0.14%, P < 0.05). Accordingly, blood levels of triglycerides (P < 0.01), urea (P < 0.001) and alanine aminotransferase (ALT) (P < 0.001) were significantly higher in group G. The homeopathic treatments produced limited effects on the milk production and immune response. However, such treatments reduced the risk of contamination of the products with medicinal traces, as H group received no allopathic treatment.     

Influence of level of zilpaterol chlorhydrate supplementation on growth performance and carcass characteristics of feedlot lambs

Forty-eight Pelibuey × Katahdin (38.8 ± 0.67 kg) crossbred male lambs were used in a 32-day feeding trial (four pens per treatment in a randomized complete block design), to evaluate the influence of zilpaterol (β₂-agonist) supplementation level on growth performance and carcass characteristics. Lambs were fed a dry-rolled corn-based finishing diet (3.04 Mcal/kg of ME) supplemented with 0, 0.15, 0.20, or 0.25 mg/kg of live weight d⁻¹ zilpaterol (as zilpaterol chlorhydrate, Zilmax^®, Intervet México, México City). DM intake averaged 1.099 ± 0.042 kg/d and was not affected (P = 0.40) by treatments. Compared with control lambs, zilpaterol supplementation increased gain efficiency (15.8%, P < 0.03), apparent energy retention per unit DMI (10.9%, P = 0.03), and tended to increased daily gain (16%, P < 0.07) and total gain (17.7%, P < 0.08). Zilpaterol supplementation did not affect (P = 0.20) carcass weight, longissimus muscle area (LM), or fat thickness, but increased (2.3%, P = 0.04) carcass dressing percentage and reduced (36%, P < 0.01) kidney-pelvic fat. Increasing level of zilpaterol supplementation increased total weight gain (linear component, P < 0.05), gain:feed (linear component, P < 0.01), and dressing percentage (linear component, P < 0.02), and decreased (linear component, P < 0.01) kidney-pelvic fat. We conclude that zilpaterol supplementation enhances growth performance and dressing percentage in lambs in a manner comparable to that of cattle (greater muscle accretion, reduced body fat). Responses to zilpaterol was optimal when supplemented at 0.20 mg of zilpaterol/kg of live weight d⁻¹.     

Pregnancy and maternal iron deficiency stimulate hepatic CRBPII expression in rats

Iron deficiency impairs vitamin A (VA) metabolism in the rat but the mechanisms involved are unknown and the effect during development has not been investigated. We investigated the effect of pregnancy and maternal iron deficiency on VA metabolism in the mother and fetus. 54 rats were fed either a control or iron deficient diet for 2 weeks prior to mating and throughout pregnancy. Another 15 female rats followed the same diet and were used as non-pregnant controls. Maternal liver, placenta and fetal liver were collected at d21 for total VA, retinol and retinyl ester (RE) measurement and VA metabolic gene expression analysis. Iron deficiency increased maternal hepatic RE (P < .05) and total VA (P < .0001), fetal liver RE (P < .05), and decreased placenta total VA (P < .05). Pregnancy increased Cellular Retinol Binding Protein (CRBP)-II gene expression by 7 fold (P = .001), decreased VA levels (P = .0004) and VA metabolic gene expression (P < .0001) in the liver. Iron deficiency increased hepatic CRBPII expression by a further 2 fold (P = .044) and RBP4 by ~ 20% (P = .005), increased RBPR2 and decreased CRBPII, LRAT, and TTR in fetal liver, while it had no effect on VA metabolic gene expression in the placenta. Hepatic CRBPII expression is increased by pregnancy and further increased by iron deficiency, which may play an important role in VA metabolism and homeostasis. Maternal iron deficiency also alters VA metabolism in the fetus, which is likely to have consequences for development.     

Beavers (Castor canadensis) facilitate early access by Canada geese (Branta canadensis) to nesting habitat and areas of open water in Canada's boreal wetlands

Several studies demonstrate how beavers influence waterfowl habitat availability, ultimately improving waterfowl breeding success; however, no current research links beavers to early season nesting activities of Canada geese (Branta canadensis) in northern climates. We examined how beavers facilitate early access to open water for geese at Miquelon Lake Provincial Park (MLPP), Canada. We surveyed 32 active and 39 inactive beaver ponds to examine whether beavers facilitate early access to open water. Open water occurred 10.7 days earlier at active beaver ponds (mean ice-off day = 87.54, s = 13.88) than inactive ponds (mean ice-off day = 98.19, s = 9.07), especially adjacent to main lodge entrances and winter food caches. Snowpack was on average 5.9 cm shallower at active ponds. Prior to availability of open water, Canada geese exhibited intraspecific territoriality over beaver lodges as nest sites and once water was present, preferred island lodges over bank lodges. These findings support other studies that examined island nesting as protection from terrestrial predators and highlight the importance of beavers in creating open water areas earlier in the season.     

Use of tolerance values to diagnose water-quality stressors to aquatic biota in New England streams

Identification of stressors related to biological impairment is critical to biological assessments. We applied nationally derived tolerance indicator values for four water-quality variables to fish and benthic macroinvertebrate assemblages at 29 sites along an urban gradient in New England. Tolerance indicator values (TIVs), as biologically based predictors of water-quality variables, were determined for dissolved oxygen, nitrite plus nitrate (nitrate), total phosphorus, and water temperature for each site based on observed biological assemblages (TIV_O), and for expected assemblages (TIV_E). The quotient method, based on a ratio of the TIVs for observed and expected assemblages (tolerance units), was used to diagnose potential water-quality stressors. In addition, the ratio of measured water-quality values to water-quality criteria (water-quality units) was calculated for each water-quality variable to assess measured water-quality stressors. Results from a RIVPACS predictive model for benthic macroinvertebrates and Bray-Curtis dissimilarity for fish were used to classify sites into categories of good or impaired ecological condition. Significant differences were detected between good and impaired sites for all biological tolerance units (fish and benthic macroinvertebrate assemblages averaged) except for nitrate (P = 0.480), and for all water-quality units except for nitrate (P = 0.183). Diagnosis of water-quality stressors at selected sites was, in general, consistent with State-reported causes of impairment. Tolerance units for benthic macroinvertebrate and fish assemblages were significantly correlated for water temperature (P = 0.001, r = 0.63), dissolved oxygen (P = 0.001, r = 0.61), and total phosphorus (P = 0.001, r = 0.61), but not for nitrate (P = 0.059, r = −0.35). Differences between the two assemblages in site-specific diagnosis of water-quality stressors may be the result of differences in nitrate tolerance.     

Plasma visfatin,a possible prognostic marker in aneurysmal subarachnoid hemorrhage

Visfatin is linked to inflammation and associated with clinical outcomes of intracerebral hemorrhage. This study was designed to investigate whether visfatin might serve as a marker of severity and prognosis in aneurysmal subarachnoid hemorrhage. In this study, plasma visfatin levels of 172 consecutive patients and 172 sex and age-matched healthy subjects were determined using enzyme-linked immunosorbent assay. The recorded clinical outcomes included in-hospital mortality and 6-month mortality and unfavorable outcome (Glasgow Outcome Scale score of 1–3). Plasma visfatin level was substantially higher in patients than in healthy controls (92.1 ± 20.5 ng/mL vs. 12.4 ± 3.2 ng/mL; P < 0.001), was significantly associated with the World Federation of Neurological Surgeons (WFNS) score (r = 0.569, P < 0.001) and Fisher score (r = 0.657, P < 0.001), was an independent predictor of in-hospital mortality [odds ratio (OR), 1.378; 95% confidence interval (CI), 1.036–1.866; P = 0.002] and 6-month mortality (OR, 1.261; 95% CI, 1.018–1.745; P = 0.004) and unfavorable outcome (OR, 1.207; 95% CI, 1.012–1.682; P = 0.008) in multivariate logistic regression analysis and had high predictive value for in-hospital mortality [area under curve (AUC), 0.849; 95% CI, 0.787–0.899; P < 0.001] and 6-month mortality (AUC, 0.868; 95% CI, 0.808–0.915; P < 0.001) and unfavorable outcome (AUC, 0.859; 95% CI, 0.797–0.907; P < 0.001) using receiver operating characteristic curves. AUCs of visfatin were similar to those of WFNS score and Fisher score (all P > 0.05), but visfatin did not improve the predictive values of WFNS score and Fisher score (all P > 0.05). Thus, visfatin may be associated with clinical severity of aneurysmal subarachnoid hemorrhage and also have prognostic value for clinical outcomes.     

Rahnella victoriana sp. nov., Rahnella bruchi sp. nov., Rahnella woolbedingensis sp. nov., classification of Rahnella genomospecies 2 and 3 as Rahnella variigena sp. nov. and Rahnella inusitata sp. nov., respectively and emended description of the genus Rahnella

Isolations from oak symptomatic of Acute Oak Decline, alder and walnut log tissue, and buprestid beetles in 2009–2012 yielded 32 Gram-negative bacterial strains showing highest gyrB sequence similarity to Rahnella aquatilis and Ewingella americana. Multilocus sequence analysis (using partial gyrB, rpoB, infB and atpD gene sequences) delineated the strains into six MLSA groups. Two MLSA groups contained reference strains of Rahnella genomospecies 2 and 3, three groups clustered within the Rahnella clade with no known type or reference strains and the last group contained the type strain of E. americana. DNA–DNA relatedness assays using both the microplate and fluorometric methods, confirmed that each of the five Rahnella MLSA groups formed separate taxa. Rahnella genomospecies 2 and 3 were previously not formally described due to a lack of distinguishing phenotypic characteristics. In the present study, all five Rahnella MLSA groups were phenotypically differentiated from each other and from R. aquatilis. Therefore we propose to classify the strains from symptomatic oak, alder and walnut and buprestid beetles as: Rahnella victoriana sp. nov. (type strain FRB 225^T = LMG 27717^T = DSM 27397^T), Rahnella variigena sp. nov. (previously Rahnella genomosp. 2, type strain CIP 105588^T = LMG 27711^T), Rahnella inusitata sp. nov. (previously Rahnella genomosp. 3, type strain DSM 30078^T = LMG 2640^T), Rahnella bruchi sp. nov. (type strain FRB 226^T = LMG 27718^T = DSM 27398^T) and Rahnella woolbedingensis sp. nov. (type strain FRB 227^T = LMG 27719^T = DSM 27399^T).     

Measuring voluntary quadriceps activation: Effect of visual feedback and stimulus delivery

Introduction: Quadriceps voluntary activation, assessed via the superimposed burst technique, has been extensively studied in a variety of populations as a measure of quadriceps function. However, a variety of stimulus delivery techniques have been employed, which may influence the level of voluntary activation as calculated via the central activation ratio (CAR). The purpose was to determine the effect of visual feedback, stimulus delivery, and perceived discomfort on maximal voluntary isometric contraction (MVIC) peak torque and the CAR. Methods: Quadriceps CAR was assessed in 14 individuals on two days using three stimulus delivery methods; (1) manual without visual feedback, (2) manual with visual feedback, and (3) automated with visual feedback. Results: MVIC peak torque and the CAR were not different between the automated with visual feedback (MVIC = 3.25, SE = 0.14 N m/kg; CAR = 88.63, SE = 1.75%) and manual with visual feedback (MVIC = 3.26, SE = 0.13 N m/kg, P = 0.859; CAR = 89.06, SE = 1.70%, P = 0.39) stimulus delivery methods. MVIC (2.99, SE = 0.12 N m/kg) and CAR (85.32, SE = 2.10%) were significantly lower using manual without visual feedback compared to manual with visual feedback and automated with visual feedback (CAR P < 0.001; MVIC P < 0.001). Perceived discomfort was lower in the second session (P < 0.05). Conclusion: Utilizing visual feedback ensures participant MVIC, and may provide a more accurate assessment of quadriceps voluntary activation.     

Impairment of the non-homologous end joining and homologous recombination pathways of DNA double strand break repair: Impact on spontaneous and radiation-induced mammary and intestinal tumour risk in Apcmin/+ mice

Female Apc^min/+ mice carrying the BALB/c variant of Prkdc or heterozygous knockout for Xrcc2, were sham- or 2 Gy X-irradiated as adults to compare the effect of mild impairments of double–strand break (DSB) repair pathways, non-homologous end joining (NHEJ) and homologous recombination (HR) respectively on spontaneous and radiation–induced mammary and intestinal tumorigenesis. Mice with impaired NHEJ showed no difference in incidence of spontaneous mammary tumours, compared with matched controls, (2.46 fold, P = 0.121) and significantly less following irradiation (radiation–induced excess; 0.35 fold, P = 0.008). In contrast mice with impaired HR presented with significantly less spontaneous mammary tumours than matched controls (0.33 fold, P = 0.027) and significantly more following irradiation (radiation-induced excess; 3.3 fold, P = 0.016). Spontaneous and radiation-induced intestinal adenoma multiplicity in the same groups were significantly greater than matched controls for mice with impaired NHEJ (sham; 1.29 fold, P < 0.001, radiation–induced excess; 2.55 fold, P < 0.001) and mice with impaired HR showed no significant differences (sham; 0.92 fold, P = 0.166, radiation-induced excess; 1.16, P = 0.274). Genetic insertion events were common in spontaneous tumours from NHEJ impaired mice compared with matched controls. γH2AX foci analysis suggests a significantly faster rate of DSB repair (MANOVA P < 0.001) in intestinal than mammary tissue; apoptosis was also higher in irradiated intestine.To conclude, results suggest that pathway of choice for repair of spontaneous and radiation-induced DSBs is influenced by tissue type. NHEJ appears to play a greater role in DSB repair in intestinal tissue since impairment by functional change of Prkdc significantly increases the rate of mis-repair in intestinal but not mammary tissue. HR appears to play a greater role in DSB repair in adult mammary tissue since impaired HR results in significant changes in mammary but not in the intestinal tumorigenesis. This indicates that early DNA damage response and repair is important for cancer susceptibility and plays a role in determining tissue specificity of cancer risk.     

Description of Massilia rubra sp. nov., Massilia aquatica sp. nov., Massilia mucilaginosa sp. nov., Massilia frigida sp. nov., and one Massilia genomospecies isolated from Antarctic streams,lakes and regoliths

Bacteria of the genus Massilia often colonize extreme ecosystems, however, a detailed study of the massilias from the Antarctic environment has not yet been performed. Here, sixty-four Gram-stain-negative, aerobic, motile rods isolated from different environmental samples on James Ross Island (Antarctica) were subjected to a polyphasic taxonomic study. The psychrophilic isolates exhibited slowly growing, moderately slimy colonies revealing bold pink-red pigmentation on R2A agar. The set of strains exhibited the highest 16S rRNA gene sequence similarities (99.5–99.9%) to Massilia violaceinigra B2^T and Massilia atriviolacea SOD^T and formed several phylogenetic groups based on the analysis of gyrB and lepA genes. Phenotypic characteristics allowed four of them to be distinguished from each other and from their closest relatives. Compared to the nearest phylogenetic neighbours the set of six genome-sequenced representatives exhibited considerable phylogenetic distance at the whole-genome level. Bioinformatic analysis of the genomic sequences revealed a high number of putative genes involved in oxidative stress response, heavy-metal resistance, bacteriocin production, the presence of putative genes involved in nitrogen metabolism and auxin biosynthesis. The identification of putative genes encoding aromatic dioxygenases suggests the biotechnology potential of the strains. Based on these results four novel species and one genomospecies of the genus Massilia are described and named Massilia rubra sp. nov. (P3094^T = CCM 8692^T = LMG 31213^T), Massilia aquatica sp. nov. (P3165^T = CCM 8693^T = LMG 31211^T), Massilia mucilaginosa sp. nov. (P5902^T = CCM 8733^T = LMG 31210^T), and Massilia frigida sp. nov. (P5534^T = CCM 8695^T = LMG 31212^T).     

Kinetic modeling and implementation of superior process strategies for β-galactosidase production during submerged fermentation in a stirred tank bioreactor

This paper reports development and implementation of superior fermentation strategies for β-galactosidase production by Lactobacillus acidophilus in a stirred-tank bioreactor. Process parameters (aeration and agitation) were optimized for the process by application of Central Composite Design. Aeration rate of 0.5 vvm and agitation speed of 250 rpm were most suitable for β-galactosidase production (2001.2 U/L). Further improvement of the operation in pH controlled environment resulted in 2135 U/L of β-galactosidase with productivity of 142.39 U/L h. Kinetic modeling for biomass and enzyme production and substrate utilization were carried out at the aforementioned pH controlled conditions. The logistic regression model (X₀ = 0.01 g/L; X_max = 2.948 g/L; μ_max = 0.59/h; R² = 0.97) was used for mathematical interpretation of biomass production. Mercier's model proved to be better than Luedeking–Piret model in describing β-galactosidase production (P₀ = 0.7942 U/L; P_max = 2169.3 U/L; P_r = 0.696/h; R² = 0.99) whereas the latter was more efficient in mathematical illustration of lactose utilization (m = 0.187 g/g h; Y_x/s = 0.301 g/L; R² = 0.98) among the two used in this study. Strategies like fed-batch fermentation (3694.6 U/L) and semi-continuous fermentation (5551.9 U/L) further enhanced β-galactosidase production by 1.8 and 2.8 fold respectively.     

Climatic dependency of soil organic carbon isotopic composition along the S–N Transect from 34°N to 52°N in central-east Asia

We explored the relationships between surface-soil (1–20 cm) organic carbon isotopic signatures and associated climatic factors in central-east Asia in an attempt to develop transfer functions that can be used to retrieve the paleoclimatic information stored in the thick eolian–paleosol sequences within the area. Our analysis shows that the negative correlation between the surface-soil organic δ¹³C values and the mean annual precipitation is robust (R² = 0.453; n = 196; p < 0.05) and the negative correlation with the growing-season (April–September) precipitation is more significant (R² = 0.4966; n = 196; p < 0.05). Our study further shows that the positive correlation between the surface-soil organic δ¹³C values and mean growing-season aridity is most significant (R² = 0.5805; n = 196; p < 0.05). We have smoothed both the organic δ¹³C values and the mean growing-season aridity values using a 3-point moving-window average-filter method in an attempt to remove some of random errors and found that the positive correlation between the two is further increased (R² =  0.7784; n =  192; p < 0.05). These robust linear relationships demonstrate their value in reconstructing paleoclimate changes in the study area. The documented climatic dependency of the surface-soil carbon isotopic composition in the study area might have resulted both from the humidity-related isotopic enrichment processes of the dominant C₃ plants (stomatal conductance and photosynthetic discrimination) and from the aridity-related abundance of C₄ plants (mainly Chenopodiaceae species) along the S–N bioclimatic gradient.     

Enhancement in liver SREBP-1c/PPAR-α ratio and steatosis in obese patients: Correlations with insulin resistance and n-3 long-chain polyunsaturated fatty acid depletion

Sterol receptor element-binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor-α (PPAR-α) mRNA expression was assessed in liver as signaling mechanisms associated with steatosis in obese patients. Liver SREBP-1c and PPAR-α mRNA (RT-PCR), fatty acid synthase (FAS) and carnitine palmitoyltransferase-1a (CPT-1a) mRNA (real-time RT-PCR), and n-3 long-chain polyunsaturated fatty acid (LCPUFA)(GLC) contents, plasma adiponectin levels (RIA), and insulin resistance (IR) evolution (HOMA) were evaluated in 11 obese patients who underwent subtotal gastrectomy with gastro-jejunal anastomosis in Roux-en-Y and 8 non-obese subjects who underwent laparoscopic cholecystectomy (controls). Liver SREBP-1c and FAS mRNA levels were 33% and 70% higher than control values (P < 0.05), respectively, whereas those of PPAR-α and CPT-1a were 16% and 65% lower (P < 0.05), respectively, with a significant 62% enhancement in the SREBP-1c/PPAR-α ratio. Liver n-3 LCPUFA levels were 53% lower in obese patients who also showed IR and hipoadiponectinemia over controls (P < 0.05). IR negatively correlated with both the hepatic content of n-3 LCPUFA (r = ? 0.55; P < 0.01) and the plasma levels of adiponectin (r = ? 0.62; P < 0.005). Liver SREBP-1c/PPAR-α ratio and n-3 LCPUFA showed a negative correlation (r = ? 0.48; P < 0.02) and positive associations with either HOMA (r = 0.75; P < 0.0001) or serum insulin levels (r = 0.69; P < 0.001). In conclusion, liver up-regulation of SREBP-1c and down-regulation of PPAR-α occur in obese patients, with enhancement in the SREBP-1c/PPAR-α ratio associated with n-3 LCPUFA depletion and IR, a condition that may favor lipogenesis over FA oxidation thereby leading to steatosis.