Black titanium oxide: synthesis, modification, characterization, physiochemical properties, and emerging applications for energy conversion and storage, and environmental sustainability.

Since its advent in 2011, black titanium oxide (B-TiOx) has garnered significant attention due to its exceptional optical characteristics, notably its enhanced absorption spectrum ranging from 200 to 2000 nm, in stark contrast to its unmodified counterpart. The escalating urgency to address global climate change has spurred intensified research into this material for sustainable hydrogen production through thermal, photocatalytic, electrocatalytic, or hybrid water-splitting techniques. The rapid advancements in this dynamic field necessitate a comprehensive update. In this review, we endeavor to provide a detailed examination and forward-looking insights into the captivating attributes, synthesis methods, modifications, and characterizations of B-TiOx, as well as a nuanced understanding of its physicochemical properties. We place particular emphasis on the potential integration of B-TiOx into solar and electrochemical energy systems, highlighting its applications in green hydrogen generation, CO2 reduction, and supercapacitor technology, among others. Recent breakthroughs in the structure-property relationship of B-TiOx and its applications, grounded in both theoretical and empirical studies, are underscored. Additionally, we will address the challenges of scaling up B-TiOx production, its long-term stability, and economic viability to align with ambitious future objectives.

Phenotypic traits related to methane emissions from Holstein dairy cows challenged by low or high forage proportion.

Limited literature is available identifying phenotypical traits related to enteric methane (CH4) production from dairy cows, despite its relevance in relation to breeding for animals with a low CH4 yield (g/kg DMI), and the derived consequences hereof. This study aimed to investigate the relationships between CH4 yield and different animal phenotypes when 16 2nd parity dairy cows, fitted with a ruminal cannula, were fed 2 diets differing in forage:concentrate ratio in a crossover design. The diets had either a low forage proportion (35% on DM basis, F35) or a high forage proportion (63% on DM basis, F63). Gas exchange was measured by means of indirect calorimetry. Spot samples of feces were collected, and indigestible NDF (INDF) was used as an internal marker to determine total-tract digestibility. In addition, ruminal evacuations, monitoring of chewing activity, determination of ruminal VFA concentration, analysis of relative abundance of methanogens, and measurement of liquid passage rate were performed. Statistical differences were analyzed by a linear mixed model with diet, days in milk, and period as fixed effects, and cow as random effect. The random cow estimates (RCE) were extracted from the model to get the Pearson correlations (r) between RCE of CH4 yield with RCE of all other variables measured, to identify possible phenotypes related to CH4 yield. Significant correlations were observed between RCE of CH4 yield and RCE of OM digestibility (r = 0.63) and ruminal concentration of valeric acid (r = -0.61), acetic acid (r = 0.54), ammonium (r = 0.55), and lactic acid (r = ‒0.53). Additionally, tendencies were observed for correlations between RCE of CH4 yield and RCE of H2 yield in g/kg DM (r = 0.47, P = 0.07), and ruminal isobutyric acid concentration (r = 0.43, P = 0.09). No correlations were observed between RCE of CH4 yield and RCE of ruminal pool sizes, milk data, urinary measurements, or chewing activity. Cows had a lower DMI and ECM, when they were fed F63 compared with F35. Cows fed F63 had higher NDF digestibility, CH4 emissions (g/d, g/kg of DMI, and g/kg of ECM), ruminal concentration of acetic acid, ruminal pH, degradation rate of digestible NDF (DNDF, %/h), and longer rumen retention time (h). Also, rumination and total chewing time (min/kg DMI) were higher for cows fed F63. The results in the present study emphasize the positive relation between cow's ability to digest OM and their CH4 emissions. The derived consequences of breeding for lower CH4 emission might be cows with lower ability to digest OM, but more studies are warranted for further documentation of this relationship.

Transposon mutagenesis screen in Klebsiella pneumoniae identifies genetic determinants required for growth in human urine and serum.

Klebsiella pneumoniae is a global public health concern due to the rising myriad of hypervirulent and multidrug-resistant clones both alarmingly associated with high mortality. The molecular mechanisms underpinning these recalcitrant K. pneumoniae infection, and how virulence is coupled with the emergence of lineages resistant to nearly all present-day clinically important antimicrobials, are unclear. In this study, we performed a genome-wide screen in K. pneumoniae ECL8, a member of the endemic K2-ST375 pathotype most often reported in Asia, to define genes essential for growth in a nutrient-rich laboratory medium (Luria-Bertani [LB] medium), human urine, and serum. Through transposon directed insertion-site sequencing (TraDIS), a total of 427 genes were identified as essential for growth on LB agar, whereas transposon insertions in 11 and 144 genes decreased fitness for growth in either urine or serum, respectively. These studies not only provide further knowledge on the genetics of this pathogen but also provide a strong impetus for discovering new antimicrobial targets to improve current therapeutic options for K. pneumoniae infections.

Effect of carbohydrate type in silages and concentrates on feed intake, enteric methane, and milk yield from dairy cows.

Dietary carbohydrate manipulation can be used to reduce enteric CH4 emission, but few studies have focused on the interaction of the different types of carbohydrates that can affect feed intake and ruminal fermentation. Understanding this interaction is necessary to make the most out of CH4 mitigation feeding strategies using different dietary carbohydrates. The aim of this study was to test the effect on enteric CH4 emission, feed intake, and milk production response when cows were fed either grass-clover silage (GCS) or corn silage (CS) as the sole forage source (55% of dry matter, DM), in combination with either barley (BAR) or dried beet pulp (DBP) as a concentrate (21.5% of DM). A total of 24 (half first-parity and half second-parity) cows were used in a crossover design with 2 periods of 21 d each, receiving 2 of 4 diets obtained from a 2 × 2 factorial arrangement of the experimental diet. Feed intake, CH4 emission metrics, and milk production were recorded at the end of the experimental periods. The diets had NDF concentrations between 258 and 340 g/kg of DM and starch concentrations between 340 and 7.45 g/kg of DM (CS-BAR and GCS-DBP, respectively). The effects of silage and concentrate on dry matter intake (DMI) were additive, with the highest feed intake in cows fed CS-BAR, followed by cows fed CS-DBP, GCS-BAR, and GCS-DBP (21.2, 19.9, 19.1, and 18.3 kg/d, respectively). Energy corrected milk (ECM) yield was not affected by silage source in first parity cows, but it was higher for cows fed CS than cows fed GCS in second parity. The effects of silage and concentrate on CH4 production (g/d), yield (g/kg of DMI), and intensity (g/kg of ECM) were not additive, as cows fed GCS had similar responses regardless of the concentrate used, but cows fed CS had lower CH4 production, yield, and intensity when fed BAR instead of DBP. The lower CH4 production, yield, and intensity in cows fed CS-BAR compared with other diets could be partially explained by the nonlinear relationship between ruminal VFA and carbohydrates (NDF and starch) concentration reported in the literature; however, we observed a linear relationship between the acetate/propionate ratio and CH4 yield, suggesting possible other effects. The effects of silage and concentrate on the ruminal VFA were additive in first parity cows, but not in second parity cows. The interaction between dietary carbohydrate type and parity might indicate an effect of feed intake or the energy balance of the cow. Feeding cows silage and concentrate both rich in starch can result in the lowest enteric CH4 emission.

Methods for studying microbial acid stress responses: from molecules to populations.

The study of how micro-organisms detect and respond to different stresses has a long history of producing fundamental biological insights while being simultaneously of significance in many applied microbiological fields including infection, food and drink manufacture, and industrial and environmental biotechnology. This is well-illustrated by the large body of work on acid stress. Numerous different methods have been used to understand the impacts of low pH on growth and survival of micro-organisms, ranging from studies of single cells to large and heterogeneous populations, from the molecular or biophysical to the computational, and from well-understood model organisms to poorly defined and complex microbial consortia. Much is to be gained from an increased general awareness of these methods, and so the present review looks at examples of the different methods that have been used to study acid resistance, acid tolerance, and acid stress responses, and the insights they can lead to, as well as some of the problems involved in using them. We hope this will be of interest both within and well beyond the acid stress research community.

The acute effects of rumen pulse-dosing of hydrogen acceptors during methane inhibition with nitrate or 3-nitrooxypropanol in dairy cows.

Dietary methane (CH4) mitigation is in some cases associated with an increased hydrogen (H2) emission. The objective of the present study was to investigate the acute and short-term effects of acceptors for H2 (fumaric acid, acrylic acid, or phloroglucinol) supplemented via pulse-dosing to dairy cows fed CH4 mitigating diets (using nitrate or 3-nitrooxypropanol), on gas exchange, rumen gas, and VFA composition. For this purpose, 2 individual 4 × 4 Latin square experiments were conducted with 4 periods of 3 d (nitrate supplementation) and 7 d (3-nitrooxypropanol supplementation), respectively. In each study, 4 rumen-cannulated Danish Holstein cows were used. Each additive for CH4 mitigation was included in the ad libitum-fed diet within the 2 experiments (exp. 1 and exp. 2), to which the cows were adapted for at least 14 d. Acceptors for H2 were administered twice daily in equal portions through the rumen fistula immediately after feeding of the individual cow. In exp. 1 (nitrate), the treatments were CON-1 (no H2-acceptor), FUM-1 (fumaric acid), ACR-1 (acrylic acid), and FUM+ACR-1 (50% FUM-1 + 50% ACR-1). In exp. 2 (3-nitrooxypropanol), the 3 treatments, CON-2, FUM-2, and ACR-2, were similar to CON-1, FUM-1 and ACR-1 treatments, however the fourth treatment was PHL-2 (phloroglucinol). Gas exchanges were measured in respiration chambers, and samples of rumen liquid and headspace gas were taken in time series relative to feeding and dosing on specific days. Headspace gas was analyzed for gas composition, and rumen liquid was analyzed for VFA composition and dissolved gas concentrations. Headspace gas composition and dissolved gas concentration were only measured in exp. 2. Dry matter intake was reduced upon acrylic acid supplementation. There were no significant effects of any treatments in any experiments on H2 emission, except for a decrease in hourly H2 emission rate (g/h) at 1 h after feeding in both experiments. In exp. 2, H2 headspace proportions increased with ACR-2 supplementation, whereas dissolved concentrations were unaffected. In exp. 1, cows on ACR-1 increased propionate proportion at 1 h after feeding. In exp. 2, both FUM-2 and ACR-2 increased rumen propionate proportion in the hours after feeding and dosing. There was no effect on rumen acetate for cows on PHL-2. There was a strong positive correlation between rumen dissolved CH4 and headspace CH4 (r = 0.84), whereas the equivalent correlation was weaker for H2 (r = 0.41). For the relationship between dissolved concentrations and emissions of CH4 and H2, there was a moderate positive correlation for CH4 (r = 0.54), whereas it was weak for H2 (r = 0.28) with zero slope. In conclusion, the results suggested that fumaric acid and acrylic acid to some extent was reduced to propionate without associative effects on measures for H2 redirection. Furthermore, phloroglucinol seemed not to be metabolized in the rumen in the present study, because no effects on rumen acetate or measures of H2 were observed. Changes in H2 headspace and emission may be a poor proxy for actual changes in the rumen fluid concentration of H2.

How much can performance measures explain of the between-cow variation in enteric methane?

Enteric CH4 produced from dairy cows contributes to the emission of greenhouse gases from anthropogenic sources. Recent studies have shown that the selection of lower CH4-emitting cows is possible, but doing so would be simpler if performance measures already recorded on farm could be used, instead of measuring gas emissions from individual cows. These performance measures could be used for selection of low emitting cows. The aim of this analysis was to quantify how much of the between-cow variation in CH4 production can be explained by variation in performance measures. A dataset with 3 experiments and a total of 149 lactating dairy cows with repeated measures was used to estimate the between-cow variation (the variation between cow estimates) for performance and gas measures from GreenFeed (C-Lock, Rapid City, SD). The cow estimates were obtained with a linear mixed model with the diet within period effect as a fixed effect and the cow within experiment as a random effect. The cow estimates for CH4 production were first regressed on the performance and gas measures individually, and then performance and CO2 production measures were grouped in 3 subsets for principal component analysis and principal component regression. The variables that explained most of the between-cow variation in CH4 production were DMI (R2 = 0.44), among the performance measures, and CO2 production (R2 = 0.61), among gas measures. Grouping the measures increased the R2 to 0.53 when only performance measures were used, and to 0.66 when CO2 production was added to the significant performance measures. We found the marginal improvement to be insufficient to justify the use of grouped measures rather than an individual measure because the latter simplifies the model and avoids over-fitting. Investigation of other measures that can be explored to increase explanatory power of between-cow variation in CH4 production is briefly discussed. Finally, the use of residual CH4 as a measure for CH4 efficiency could be considered by using either DMI or CO2 production as the sole predicting variables.

On the potential role of naturally occurring carboxylic organic acids as anti-infective agents: opportunities and challenges.

Carboxylic organic acids are intermediates of central carbon metabolic pathways (e.g. acetic, propionic, citric, and lactic acid) long known to have potent antimicrobial potential, mainly at acidic pHs. The food industry has been leveraging those properties for years, using many of these acids as preservatives to inhibit the growth of pathogenic and/or spoilage fungal and bacterial species. A few of these molecules (the most prominent being acetic acid) have been used as antiseptics since Hippocratic medicine, mainly to treat infected wounds in patients with burns. With the growth of antibiotic therapy, the use of carboxylic acids (and other chemical antiseptics) in clinical settings lost relevance; however, with the continuous emergence of multi-antibiotic/antifungal resistant strains, the search for alternatives has intensified. This prospective article raises awareness of the potential of carboxylic acids to control infections in clinical settings, considering not only their previous exploitation in this context (which we overview) but also the positive experience of their safe use in food preservation. At a time of great concern with antimicrobial resistance and the slow arrival of new antimicrobial therapeutics to the market, further exploration of organic acids as anti-infective molecules may pave the way to more sustainable prophylactic and therapeutic approaches.

Exceptionally high proton conductivity in Eu2O3 by proton-coupled electron transfer mechanism.

Proton conductors are typically developed by doping to introduce structural defects such as oxygen vacancies to facilitate ionic transport through structural bulk conduction mechanism. In this study, we present a novel electrochemical proton injection method via an in situ fuel cell process, demonstrating proton conduction in europium oxide (Eu2O3) through a surficial conduction mechanism for the first time. By tuning Eu2O3 into a protonated form, H-Eu2O3, we achieved an exceptionally high proton conductivity of 0.16 S cm-1. Distribution of relaxation time (DRT) analysis was employed to investigate the proton transport behavior and reveal the significant contribution of surface proton transport to the overall conductivity of Eu2O3. Remarkably, H-Eu2O3 exhibited a low activation energy for ionic transport, comparable to the best ceramic electrolytes available. The proton-coupled electron transfer (PCET) mechanism describes this novel surficial proton conduction mechanism. These findings provide new possibilities for developing advanced proton conductors with improved performance.

Effects of dietary fat, nitrate, and 3-nitrooxypropanol and their combinations on methane emission, feed intake, and milk production in dairy cows.

The objective of the present study was to investigate the effect of individual and combined use of dietary fat, nitrate, and 3-nitrooxypropanol (3-NOP) on dairy cows' enteric methane (CH4) emission and production performance. Twenty-four primiparous and 24 multiparous Danish Holstein cows (111 ± 44.6 d in milk; mean ± standard deviation) were included in an incomplete 8 × 8 Latin square design with six 21-d periods. Dietary treatments were organized in a 2 × 2 × 2 factorial arrangement aiming for 2 levels of FAT (30 or 63 g of crude fat/kg of dry matter [DM]; LF or HF, respectively), 2 levels of NITRATE (0 or 10 g of nitrate/kg of DM; UREA or NIT, respectively), and 2 levels of 3-NOP (0 or 80 mg/kg DM; BLANK or NOP, respectively). Treatments were included in ad libitum-fed partial mixed rations in bins that automatically measured feed intake and eating behavior. Additional concentrate was offered as bait in GreenFeed units used for measurement of gas emission. For total DM intake (DMI), a FAT × NITRATE interaction showed that DMI, across parities and levels of 3-NOP, was unaffected by separate fat supplementation, but reduced by nitrate with 4.6% and synergistically decreased (significant 2-way interaction) with 13.0% when fat and nitrate were combined. Additionally, 3-NOP decreased DMI by 13.4% and the combination of 3-NOP with fat and nitrate decreased DMI in an additive way (no significant 3-way interaction). The decreasing effects on DMI were more pronounced in multiparous cows than in primiparous cows. For treatments with largest reductions in DMI, eating behavior was altered toward more frequent, but smaller meals, a slower eating rate and increased attempts to visit unassigned feed bins. Energy-corrected milk (ECM) yield increased by 6.3% with fat supplementation, whereas ECM yield did not differ among diets including nitrate (FAT × NITRATE interaction). Cows supplemented with 3-NOP had 9.0% lower ECM yield than cows fed no 3-NOP. Based on three 2-way interactions including FAT, NITRATE, and 3-NOP, the combined use of the additives resulted in antagonistic effects on CH4 reduction. A 6% to 7% reduction in CH4 yield (CH4/kg of DMI) could be ascribed to the effect of fat, a 12% to 13% reduction could be ascribed to the effect of nitrate and an 18% to 23% reduction could be ascribed to the effect of 3-NOP. Hence, no combinations of additives resulted in CH4 yield-reductions that were greater than what was obtained by separate supplementation of the most potent additive within the combination. The CH4 yield reduction potential of additives was similar between parities. Increased apparent total-tract digestibility of organic matter (OM) in cows fed combinations including nitrate or 3-NOP was a result of a NITRATE × 3-NOP interaction. Apparent total-tract digestibility of OM was also increased by fat supplementation. These increases reflected observed decreases in DMI. In conclusion, combined use of fat, nitrate, and 3-NOP in all combinations did not result in CH4 reductions that were greater than separate supplementation of the most potent additive within the combination (3-NOP > nitrate > fat). Additionally, separate supplementation of some additives and combined use of all additives reduced DMI.

Exploitation of microbial activities at low pH to enhance planetary health.

Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is, however, under-recognized that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing, and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization, or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical-chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective.

Gas exchange, rumen hydrogen sinks, and nutrient digestibility and metabolism in lactating dairy cows fed 3-nitrooxypropanol and cracked rapeseed.

Fat in the form of cracked rapeseed and 3-nitrooxypropanol (3-NOP, market as Bovaer) were fed alone or in combination to 4 Danish Holstein multicannulated dairy cows, with the objective to investigate effects on gas exchange, dry matter intake (DMI), nutrient digestion, and nutrient metabolism. The study design was a 4 × 4 Latin square with a 2 × 2 factorial treatment arrangement with 2 levels of fat supplementation; 33 g of crude fat per kg of dry matter (DM) or 64 g of crude fat per kg of DM for low and high fat diets, respectively, and 2 levels of 3-NOP; 0 mg/kg DM or 80 mg/kg DM. In total, 4 diets were formulated: low fat (LF), high fat (HF), 3-NOP and low fat (3LF), and 3-NOP and high fat (3HF). Cows were fed ad libitum and milked twice daily. The adaptation period lasted 11 d, followed by 5 d with 12 diurnal sampling times of digesta and ruminal fluid. Thereafter, gas exchange was measured for 5 d in respiration chambers. Chromic oxide and titanium dioxide were used as external flow markers to determine intestinal nutrient flow. No interactions between fat supplementation and 3-NOP were observed for methane yield (g/kg DM), total-tract digestibility of nutrients or total volatile fatty acid (VFA) concentration in the rumen. Methane yield (g/kg DMI) was decreased by 24% when cows were fed 3-NOP. In addition, 3-NOP increased carbon dioxide and hydrogen yield (g/kg DM) by 6% and 3,500%, respectively. However, carbon dioxide production was decreased when expressed on a daily basis. Fat supplementation did not affect methane yield but tended to reduce methane in percent of gross energy intake. A decrease (11%) in DMI was observed, when cows were fed 3-NOP. Likely, the lower DMI mediated a lower passage rate causing the tendency to higher rumen and total-tract neutral detergent fiber digestibility, when the cows were fed 3-NOP. Total VFA concentrations in the rumen were negatively affected both by 3-NOP and fat supplementation. Furthermore, 3-NOP caused a shift in the VFA fermentation profile, with decreased acetate proportion and increased butyrate proportion, whereas propionate proportion was unaffected. Increased concentrations of the alcohols methanol, ethanol, propanol, butanol, and 2-butanol were observed in the ruminal fluid when cows were fed 3-NOP. These changes in rumen metabolites indicate partial re-direction of hydrogen into other hydrogen sinks, when methanogenesis is inhibited by 3-NOP. In conclusion, fat supplementation did not reduce methane yield, whereas 3-NOP reduced methane yield, irrespective of fat level. However, the concentration of 3-NOP and diet composition and resulting desired mitigation effect must be considered before implementation. The observed reduction in DMI with 80 mg 3-NOP/kg DM was intriguing and may indicate that a lower dose should be applied in a Northern European context; however, the mechanism behind needs further investigation.

Recovery, Regeneration, and Reapplication of PFSA Polymer from End-of-Life PEMFC MEAs.

We have developed a recovery, regeneration, and reapplication process for Nafion, a perfluorinated sulfonic acid (PFSA) ionomer, from end-of-life (EoL) low-temperature proton-exchange membrane (PEM) fuel cells (FCs). Samples of PFSA PEM recovered from EoL membrane-electrode assemblies (MEAs) with a history of close to 19,000 h of operation were recycled by dissolving the polymeric material in ethanol and applying the dissolved PFSA ionomer for producing the ionomer phase of the catalyst layer of new PEMFC cathodes. Structural characterizations show a marginally lower abundance of sulfonic groups for the EoL PEM compared to a fresh sample. Sulfonation of the former was employed to regenerate sulfonic groups to compensate for the lost ones. New gas-diffusion electrodes (GDEs) were prepared with the recycled PFSA ionomer both with and without sulfonation, and MEAs with these GDEs as cathodes were assembled through a state-of-the-art procedure. Electrochemical characterizations of the GDEs and single-cell studies of the MEAs showed that the electrochemical performances of catalyst layers containing recycled PFSA ionomer were at least similar to those containing fresh. Durability studies of the GDEs and MEAs, performed through a three-electrode liquid cell and a single cell, respectively, show the highest durability for the GDE/MEA with PFSA ionomer recycled without applying the sulfonation step. However, the GDE with PFSA ionomer obtained from recycling a re-sulfonated PEM shows a durability comparable to that of the GDE with fresh PFSA ionomer. Hence, PFSA material aged during PEMFC operation may be employed to produce highly functional and durable regenerated PFSA ionomer for PEMFC catalyst layers. The studied process of PFSA ionomer recycling is highly attractive for industrial adoption.

Enteric methane emission of dairy cows supplemented with iodoform in a dose-response study.

Enteric methane (CH4) emission is one of the major greenhouse gasses originating from cattle. Iodoform has in studies been found to be a potent mitigator of rumen CH4 formation in vitro. This study aimed to quantify potential of iodoform as an anti-methanogenic feed additive for dairy cows and investigate effects on feed intake, milk production, feed digestibility, rumen microbiome, and animal health indicators. The experiment was conducted as a 4 × 4 Latin square design using four lactating rumen, duodenal, and ileal cannulated Danish Holstein dairy cows. The treatments consisted of four different doses of iodoform (1) 0 mg/day, (2) 320 mg/day, (3) 640 mg/day, and (4) 800 mg/day. Iodoform was supplemented intra-ruminally twice daily. Each period consisted of 7-days of adaptation, 3-days of digesta and blood sampling, and 4-days of gas exchange measurements using respiration chambers. Milk yield and dry matter intake (DMI) were recorded daily. Rumen samples were collected for microbial analyses and investigated for fermentation parameters. Blood was sampled and analyzed for metabolic and health status indicators. Dry matter intake and milk production decreased linearly by maximum of 48% and 33%, respectively, with increasing dose. Methane yield (g CH4/kg DMI) decreased by maximum of 66%, while up to 125-fold increases were observed in hydrogen yield (g H2/kg DMI) with increasing dose of iodoform. Total tract digestibility of DM, OM, CP, C, NDF, and starch were unaffected by treatments, but large shifts, except for NDF, were observed for ruminal to small intestinal digestion of the nutrients. Some indicators of disturbed rumen microbial activity and fermentation dynamics were observed with increasing dose, but total number of ruminal bacteria was unaffected by treatment. Serum and plasma biomarkers did not indicate negative effects of iodoform on cow health. In conclusion, iodoform was a potent mitigator of CH4 emission. However, DMI and milk production were negatively affected and associated with indications of depressed ruminal fermentation. Future studies might reveal if depression of milk yield and feed intake can be avoided if iodoform is continuously administered by mixing it into a total mixed ration.

Effect of nitrate supplementation, dietary protein supply, and genetic yield index on performance, methane emission, and nitrogen efficiency in dairy cows.

The objective was to investigate the effect of nonprotein nitrogen source, dietary protein supply, and genetic yield index on methane emission, N metabolism, and ruminal fermentation in dairy cows. Forty-eight Danish Holstein dairy cows (24 primiparous cows and 24 multiparous cows) were used in a 6 × 4 incomplete Latin square design with 4 periods of 21-d duration. Cows were fed ad libitum with the following 6 experimental diets: diets with low, medium, or high rumen degradable protein (RDP):rumen undegradable protein (RUP) ratio (manipulated by changing the proportion of corn meal, corn gluten meal, and corn gluten feed) combined with either urea or nitrate (10 g NO3-/kg of dry matter) as nonprotein nitrogen source. Samples of ruminal fluid and feces were collected from multiparous cows, and total-tract nutrient digestibility was estimated using TiO2 as flow marker. Milk samples were collected from all 48 cows. Gas emission (CH4, CO2, and H2) was measured by 4 GreenFeed units. We observed no significant interaction between dietary RDP:RUP ratio and nitrate supplementation, and between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity). As dietary RDP:RUP ratio increased, intake of crude protein, RDP, and neutral detergent fiber and total-tract digestibility of crude protein linearly increased, and RUP intake linearly decreased. Yield of milk, energy-corrected milk, and milk protein and lactose linearly decreased, whereas milk fat and milk urea nitrogen concentrations linearly increased as dietary RDP:RUP ratio increased. The increase in dietary RDP:RUP ratio resulted in a linear increase in the excretion of total purine derivatives and N in urine, but a linear decrease in N efficiency (milk N in % of N intake). Nitrate supplementation reduced dry matter intake (DMI) and increased total-tract organic matter digestibility compared with urea supplementation. Nitrate supplementation resulted in a greater reduction in DMI and daily CH4 production and a greater increase in daily H2 production in multiparous cows compared with primiparous cows. Nitrate supplementation also showed a greater reduction in milk protein and lactose yield in multiparous cows than in primiparous cows. Milk protein and lactose concentrations were lower for cows receiving nitrate diets compared with cows receiving urea diets. Nitrate supplementation reduced urinary purine derivatives excretion from the rumen, whereas N efficiency tended to increase. Nitrate supplementation reduced proportion of acetate and propionate in ruminal volatile fatty acids. In conclusion, no interaction was observed between dietary RDP:RUP ratio and nitrate supplementation, and no interaction between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity) was noted. Nitrate supplementation resulted in a greater reduction in DMI and CH4 production, and a greater increase in H2 production in multiparous cows than in primiparous cows. As the dietary RDP:RUP ratio increased, CH4 emission was unaffected and RDP intake increased, but RUP intake and milk yield decreased. Genetic yield index did not affect CH4 production, yield, or intensity.

Dietary supplementation with xylooligosaccharides and exogenous enzyme improves milk production, energy utilization efficiency and reduces enteric methane emissions of Jersey cows.

BACKGROUND: Sustainable strategies for enteric methane (CH4) mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure. The present study aimed to investigate the effects of dietary xylooligosaccharides (XOS) and exogenous enzyme (EXE) supplementation on milk production, nutrient digestibility, enteric CH4 emissions, energy utilization efficiency of lactating Jersey dairy cows. Forty-eight lactating cows were randomly assigned to one of 4 treatments: (1) control diet (CON), (2) CON with 25 g/d XOS (XOS), (3) CON with 15 g/d EXE (EXE), and (4) CON with 25 g/d XOS and 15 g/d EXE (XOS + EXE). The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period. The enteric CO2 and CH4 emissions and O2 consumption were measured using two GreenFeed units, which were further used to determine the energy utilization efficiency of cows. RESULTS: Compared with CON, cows fed XOS, EXE or XOS + EXE significantly (P < 0.05) increased milk yield, true protein and fat concentration, and energy-corrected milk yield (ECM)/DM intake, which could be reflected by the significant improvement (P < 0.05) of dietary NDF and ADF digestibility. The results showed that dietary supplementation of XOS, EXE or XOS + EXE significantly (P < 0.05) reduced CH4 emission, CH4/milk yield, and CH4/ECM. Furthermore, cows fed XOS demonstrated highest (P < 0.05) metabolizable energy intake, milk energy output but lowest (P < 0.05) of CH4 energy output and CH4 energy output as a proportion of gross energy intake compared with the remaining treatments. CONCLUSIONS: Dietary supplementary of XOS, EXE or combination of XOS and EXE contributed to the improvement of lactation performance, nutrient digestibility, and energy utilization efficiency, as well as reduction of enteric CH4 emissions of lactating Jersey cows. This promising mitigation method may need further research to validate its long-term effect and mode of action for dairy cows.

Mycobacterial chaperonins in cellular proteostasis: Evidence for chaperone function of Cpn60.1 and Cpn60.2-mediated protein folding.

Mycobacterium tuberculosis encodes two chaperonin proteins, MtbCpn60.1 and MtbCpn60.2, that share substantial sequence similarity with the Escherichia coli chaperonin, GroEL. However, unlike GroEL, MtbCpn60.1 and MtbCpn60.2 purify as lower-order oligomers. Previous studies have shown that MtbCpn60.2 can functionally replace GroEL in E. coli, while the function of MtbCpn60.1 remained an enigma. Here, we demonstrate the molecular chaperone function of MtbCpn60.1 and MtbCpn60.2, by probing their ability to assist the folding of obligate chaperonin clients, DapA, FtsE and MetK, in an E. coli strain depleted of endogenous GroEL. We show that both MtbCpn60.1 and MtbCpn60.2 support cell survival and cell division by assisting the folding of DapA and FtsE, but only MtbCpn60.2 completely rescues GroEL-depleted E. coli cells. We also show that, unlike MtbCpn60.2, MtbCpn60.1 has limited ability to support cell growth and proliferation and assist the folding of MetK. Our findings suggest that the client pools of GroEL and MtbCpn60.2 overlap substantially, while MtbCpn60.1 folds only a small subset of GroEL clients. We conclude that the differences between MtbCpn60.1 and MtbCpn60.2 may be a consequence of their intrinsic sequence features, which affect their thermostability, efficiency, clientomes and modes of action.

Toward next-generation fuel cell materials.

The fuel cell's three layers-anode/electrolyte/cathode-convert fuel's chemical energy into electricity. Electrolyte membranes determine fuel cell types. Solid-state and ceramic electrolyte SOFC/PCFC and polymer based PEMFC fuel cells dominate fuel cell research. We present a new fuel cell concept using next-generation ceramic nanocomposites made of semiconductor-ionic material combinations. A built-in electric field driving mechanism boosts ionic (O2- or H+ or both) conductivity in these materials. In a fuel cell device, non-doped ceria or its heterostructure might attain 1 Wcm-2 power density. We reviewed promising functional nanocomposites for that range. Ceria-based and multifunctional semiconductor-ionic electrolytes will be highlighted. Owing to their simplicity and abundant resources, these materials might be used to make fuel cells cheaper and more accessible.

Is Another kind of Biologization Possible? On Biology and the psy Sciences.

The relationship between biology and the psy disciplines (psychology, psychiatry, and psychotherapy) is a complex one. Many scholars have criticized how these disciplines have been biologized in the 20th century, especially since the emergence of psychopharmacology, neuroscience, and genetic research. However, biology is not just a laboratory-based science of chemical compounds, scanners, and DNA sequencing, but also a field science based on observations of organisms in their milieus. In this paper, we draw a contrast between laboratory-based biology with a focus on brains and genes, and an ecology-based biology with a focus on lives and niches. Our argument is philosophical in nature - building partly on Wittgenstein as a "philosopher of life" - to the effect that the psy sciences need not just less biologization of the former kind, but also more biologization of the latter kind to avoid a prevalent mentalism. Not least when it comes to an understanding of psychological distress, which can favorably be viewed situationally and coupled to human lives in ecological niches.