Controlled biocatalytic synthesis of a metal nanoparticle-enzyme hybrid: demonstration for catalytic H2-driven NADH recycling

Here we demonstrate the preparation of enzyme-metal biohybrids of NAD+ reductase with biocatalytically-synthesised small gold nanoparticles (NPs, <10 nm) and core-shell gold-platinum NPs for tandem catalysis. Despite the variety of methods available for NP synthesis, there remains a need for more sustainable strategies which also give precise control over the shape and size of the metal NPs for applications in catalysis, biomedical devices, and electronics. We demonstrate facile biosynthesis of spherical, highly uniform, gold NPs under mild conditions using an isolated enzyme moiety, an NAD+ reductase, to reduce metal salts while oxidising a nicotinamide-containing cofactor. By subsequently introducing platinum salts, we show that core-shell Au@Pt NPs can then be formed. Catalytic function of these enzyme-Au@Pt NP hybrids was demonstrated for H2-driven NADH recycling to support enantioselective ketone reduction by an NADH-dependent alcohol dehydrogenase

Is the objective food environment associated with perceptions of the food environment?

Objective The present study examined whether objective measures of the food environment are associated with perceptions of the food environment and whether this relationship varies by socio-economic disadvantage.Design The study is a cross-sectional analysis of self-report surveys and objective environment data. Women reported their perceptions on the nutrition environment. Participants&rsquo; homes and food stores were geocoded to measure the objective community nutrition environment. Data on the average price and variety of fruit and vegetables were used to measure the objective consumer nutrition environment.Setting The study was conducted in Melbourne, Australia, in 2003&ndash;2004.Subjects Data presented are from a sample of 1393 women aged 18&ndash;65 years.Results Overall the match between the perceived and objective environment was poor, underscoring the limitations in using perceptions of the environment as a proxy for the objective environment. Socio-economic disadvantage had limited impact on the relationship between perceived and objective nutrition environment.Conclusions Further research is needed to understand the determinants of perceptions of the nutrition environment to enhance our understanding of the role of perceptions in nutrition choices and drivers of socio-economic inequalities in nutrition.<br /

Use Of Wildlife Crossing Structures On Us Highway 93 On The Flathead Indian Reservation

In the 1990s, Montana Department of Transportation (MDT) proposed an expansion of U.S. Highway 93, in an area entirely within the Flathead Indian Reservation (FIR), home to the Confederated Salish and Kootenai Tribes (CSKT). In December 2000, the CSKT, MDT, and Federal Highway Administration (FHWA) signed a memorandum of agreement that enabled its expansion. It included wildlife mitigation measures to both mitigate impacts to wildlife and natural processes associated with the widening of US93 as well as to address the safety of the traveling public. Mitigation measures include 41 fish and wildlife-crossing structures, including 40 underpasses and one overpass, wildlife fencing, jumpouts, and wildlife crossing guards across 56 mi of highway. Crossing structures were placed in areas that have a history of wildlife crossings and wildlife mortality, and/or locations where the surrounding landscape and land use was best suited for the crossing structures. Research is underway to determine the effectiveness of the mitigation (see www.mdt.mt.gov/research/ projects/env/wildlife_crossing.shtml). Between May 2008 and December 2009, eleven underpasses were monitored for wildlife use. Wildlife use of the structures was substantial with 3,000 deer crossings, 1500 coyote crossings, 300 bobcat crossings, 200 raccoon crossings, and 200 black bear crossings. Other species that used the crossings include mountain lion, elk, grizzly bear, moose, badger, river otter, muskrat, beaver, skunk, rabbit, and various bird species. For the wildlife mitigation measures to be considered successful, goals have been set by the CSKT, MDT, and FHWA, and more data need to be collected and analyzed before the researchers can conclude whether the mitigation measures have indeed reached those goals

Enhancing Oxygen Uptake Efficiency Through Nasal Breathing in Aerobic Exercise

An individual’s ability to use oxygen to sustain aerobic performance, as denoted by the oxygen uptake efficiency (OUE), is calculated by dividing oxygen uptake (VO2) by ventilation (VE). Whether nasal breathing (NB) during exercise would improve OUE more significantly compared to combined breathing (CB) remains uncertain. PURPOSE: To determine the effects of utilizing NB during exercise on OUE. METHODS: Fourteen males (age: 20.57 ± 1.22 yrs; BMI: 26.03 ± 3.16 kg/m2) were randomly assigned to the NB (n = 8) or CB (n = 6) group for a 4-week supervised aerobic exercise intervention conducted four times per week for 30 minutes at moderate intensity (70% maximal heart rate). VO2max tests were performed during the pre- (week 0) and post-study (week 4) periods on a recumbent bike to determine the change in OUE, VO2, and VE at varying intensities (40%, 55%, 70%, 85%, and 100% of VO2max). The OUE was calculated as VO2 (L) ÷ VE (L). A one-way ANCOVA, controlling for OUE, VO2, and VE at pre-study, was utilized to examine if NB elicited cardiorespiratory adaptations that were superior to the CB training at post-study. A paired-sample t-test examined changes in OUE, VO2, and VE throughout the GXT from week 0 to week 4. Data are presented as mean ± standard error. RESULTS: The NB group demonstrated significantly greater [F(1,11) = 7.213, p = 0.021] OUE (0.048 ± 0.002) at 85% of VO2max than the CB (0.037 ± 0.003) group. Similarly, the NB group had a significantly greater (p = 0.014) OUE (0.025 ± 0.001) at 100% of VO2max than the CB (0.021 ± 0.001) group. Only the NB group experienced significant improvements after exercise training in VO2 at 40% ( p = 0.003, 12.02 ± 0.50 to 13.72 ± 0.59 mL·kg·min-1], 55% (p = 0.006, 16.68 ± 0.71 to 18.87 ± 0.81 mL·kg·min-1), 70% (p = 0.005, 21.16 ± 0.93 to 24.00 ± 1.01 mL·kg·min-1), 85% (p = 0.004, 25.81 ± 1.11 to 29.03 ± 1.23 mL·kg·min-1), and 100% VO2max (p = 0.005, 30.31 ± 1.30 to 34.18 ± 1.48 mL·kg·min-1). While not statistically significant, the NB group displayed a trend of reduced VE compared to the CB group. CONCLUSION: The integration of NB during aerobic exercise enhanced the OUE, particularly at higher intensities, compared to CB. This adaptation is noteworthy, as the NB group achieved a comparable range of VO2 as the CB group while maintaining a lower VE after just 1-month of training. This denotes that NB could promote enhanced oxygen movement. Future studies are warranted to investigate additional health adaptations resulting from such training benefits

Authenticity of the Ratio of Inorganic Phosphate to Phosphocreatine as a Marker for Respiratory Stress During a Maximal Aerobic Exercise

Under the context of assessing the effects of mitochondrial stress on skeletal muscles, consideration for the ratio of inorganic phosphate to phosphocreatine (Pi:PCr) may be used as a surrogate marker. Furthermore, assessing the systemic Pi:PCr, under states of high metabolic and respiratory demands with reduced oxygen supply (VO2), such as strenuous exercise while only using nasal breathing (NB), might provide valuable information regarding respiratory strain to a given exercise bout. PURPOSE: To determine if the systemic assessment of the Pi:PCr ratio can serve as an indicator of respiratory stress. METHODS: Fourteen young males (age = 20.57 ± 1.22 yrs) completed a graded maximal exercise test (GXT) on a recumbent bike using either NB (n = 8) or combined (CB, n = 6) breathing. Plasma Pi and PCr were measured pre- and immediately post-GXT. Pi was analyzed using the malachite green colorimetric method, and PCr was quantified via sandwich enzyme-linked immunosorbent assay. The Pi:PCr was calculated by Pi ÷ PCr. A paired-sample t-test examined the Pi: PCr change following a GXT. A Pearson correlational analysis examined the relationship between the Pi:PCr and the respiratory performance during preset intensities (40%, 55%, 70%, 85%, and 100% VO2max). Data are presented as mean ± SD. RESULTS: The Pi:PCr ratio significantly decreased in the NB group (0.589 ± 0.313 to 0.530 ± 0.304, p = 0.034) mainly due to the elevated PCr (601.68 ± 318.88 mmol/L to 689.40 ± 410.60 mmol/L, p = 0.033). The Pi:PCR ratio was negatively correlated with VO2 only in the NB group throughout all preset intensities of the GXT. After controlling for the pre-GXT Pi:PCr as a covariate, the NB group showed a non-significant (p = 0.340) but higher mean concentration for post-exercise Pi:PCr compared to the CB group [NB: 0.451 ± 0.027 mmol/L versus CB: 0.407 ± 0.320 mmol/L. CONCLUSION: The results from the present study suggest that the assessment of the Pi:PCr ratio could serve as a valuable marker of physical strain pertaining to high respiratory demands. Moreover, the assignment of NB during exercise is becoming a novel method due to its postulated benefits towards respiratory function, which may induce a more significant cellular stress as denoted by an increase in the post-exercise Pi:PCr ratio

Biochemical and genetic studies define the functions of methylthiotransferases in methanogenic and methanotrophic archaea

Methylthiotransferases (MTTases) are radical S-adenosylmethionine (SAM) enzymes that catalyze the addition of a methylthio (-SCH3) group to an unreactive carbon center. These enzymes are responsible for the production of 2-methylthioadenosine (ms2A) derivatives found at position A37 of select tRNAs in all domains of life. Additionally, some bacteria contain the RimO MTTase that catalyzes the methylthiolation of the S12 ribosomal protein. Although the functions of MTTases in bacteria and eukaryotes have been established via detailed genetic and biochemical studies, MTTases from the archaeal domain of life are understudied and the substrate specificity determinants of MTTases remain unclear. Here, we report the in vitro enzymatic activities of an MTTase (C4B56_06395) from a thermophilic Ca. Methanophagales anaerobic methanotroph (ANME) as well as the MTTase from a hyperthermophilic methanogen – MJ0867 from Methanocaldococcus jannaschii. Both enzymes catalyze the methylthiolation of N6-threonylcarbamoyladenosine (t6A) and N6-hydroxynorvalylcarbamoyladenosine (hn6A) residues to produce 2-methylthio-N6-threonylcarbamoyladenosine (ms2t6A) and 2-methylthio-N6-hydroxynorvalylcarbamoyladenosine (ms2hn6A), respectively. To further assess the function of archaeal MTTases, we analyzed select tRNA modifications in a model methanogen – Methanosarcina acetivorans – and generated a deletion of the MTTase-encoding gene (MA1153). We found that M. acetivorans produces ms2hn6A in exponential phase of growth, but does not produce ms2t6A in detectable amounts. Upon deletion of MA1153, the ms2A modification was absent, thus confirming the function of MtaB-family MTTases in generating ms2hn6A modified nucleosides in select tRNAs

Loss of Nmp4 optimizes osteogenic metabolism and secretion to enhance bone quality

A goal of osteoporosis therapy is to restore lost bone with structurally sound tissue. Mice lacking the transcription factor Nuclear Matrix Protein 4 (Nmp4, Zfp384, Ciz, ZNF384) respond to several classes of osteoporosis drugs with enhanced bone formation compared to wild type (WT) animals. Nmp4-/- mesenchymal stem/progenitor cells (MSPCs) exhibit an accelerated and enhanced mineralization during osteoblast differentiation. To address the mechanisms underlying this hyper-anabolic phenotype, we carried out RNA-sequencing and molecular and cellular analyses of WT and Nmp4-/- MSPCs during osteogenesis to define pathways and mechanisms associated with elevated matrix production. We determined that Nmp4 has a broad impact on the transcriptome during osteogenic differentiation, contributing to the expression of over 5,000 genes. Phenotypic anchoring of transcriptional data was performed for the hypothesis-testing arm through analysis of cell metabolism, protein synthesis and secretion, and bone material properties. Mechanistic studies confirmed that Nmp4-/- MSPCs exhibited an enhanced capacity for glycolytic conversion- a key step in bone anabolism. Nmp4-/- cells showed elevated collagen translation and secretion. Expression of matrix genes that contribute to bone material-level mechanical properties were elevated in Nmp4-/- cells, an observation that was supported by biomechanical testing of bone samples from Nmp4-/- and WT mice. We conclude that loss of Nmp4 increases the magnitude of glycolysis upon the metabolic switch, which fuels the conversion of the osteoblast into a super-secretor of matrix resulting in more bone with improvements in intrinsic quality

A Systematic Review of Chronic Pain Mechanism Differential Assessment Strategies for Physical Therapy

Background Recently, the International Association for the Study of Pain (IASP) redefined pain, the American Physical Therapy Association proposed pain education guidelines, and a new pain mechanism category (PMC) was defined as “nociplastic pain”. IASP defines three PMCs - nociceptive, neuroplastic, and nociplastic. Purpose Identify current clinical assessment strategies for differentiating between nociceptive, neuropathic, and nociplastic chronic pain, feasible for implementation by physical therapists (PTs). Methods In 2020, investigators independently searched databases for studies evaluating assessment methods differentiating “nociceptive,” “neuropathic,” “central,” “mixed pain” and “central sensitization,” with follow-up on “nociplastic pain”. A qualitative systematic review was performed utilizing defined inclusion and exclusion criteria, priori criteria for independent evaluation of search result abstracts, blind voting that resulted in inclusion of 91 articles, and a piloted form for data extraction. Results PMC assessments were categorized into 4 strategies, recommending combined strategies for meaningful diagnosis. 30% of articles analyzed PMCs per specific pathology, while debating pathology-based pain phenotyping and assessment. PMC nociplastic studies’ agreements included: PMC diagnostic features may be shared, they are not always independent, and may evolve into a blended continuum as chronic pain develops. Studies presented PMC conceptualization, highlighting terminology inconsistencies and understanding amongst researchers, clinicians, and educators. Conclusion High quality research is emerging to inform the physical therapy clinician on differential assessment strategies for pain mechanisms in chronic pain patients. The ability for PTs to assess and treat chronic pain is challenged by the current lack of continuity within PMC education, terminology, and difficulty of in vivo research on the subject

Brokering in the Classroom: OST Partnerships with Schools to Connect Youth to Future Learning Opportunities

When OST organizations bring projects into the classroom, they have an opportunity to act as learning brokers that can support the futures of a great number of young people. This brief discusses some key strategies to consider.Spencer Foundation; New York Community Trust; Capital On

Isolation, small population size, and management influence inbreeding and reduced genetic variation in K’gari dingoes

Small island populations are vulnerable to genetic decline via demographic and environmental stochasticity. In the absence of immigration, founder effects, inbreeding and genetic drift are likely to contribute to local extinction risk. Management actions may also have a greater impact on small, closed populations. The demographic and social characteristics of a species can, however, delay the impact of threats. K’gari, a ~ 1 660 km2 island off the Australian east coast and UNESCO World Heritage Site (Fraser Island 1842–2023), supports an isolated population of approximately 70–200 dingoes that represent an ideal opportunity to explore the small island paradigm. To examine temporal and spatial patterns of genetic diversity in this population we analysed single nucleotide polymorphism (SNP) genotype data (72 454 SNPS) for 112 K’gari dingoes collected over a 25-year period (1996 to 2020). Genetic diversity was lower in K’gari dingoes than mainland dingoes at the earliest time point in our study and declined significantly following a management cull in 2001. We did not find any spatial genetic patterns on the island, suggesting high levels of genetic connectivity between socially discrete packs. This connectivity, combined with the social structure and behaviour of dingoes, may act in concert to buffer the population from the impacts of genetic drift in the short term. Nevertheless, a general decline in genetic variation via inbreeding and drift has occurred over the past 20 years which we suggest should be considered in any future management planning for the population. Monitoring patterns of genetic variation, together with a clearer understanding of the social ecology of K’gari dingoes, will aid in the development of measurable genetic targets set over ecologically meaningful timelines, and help ensure continued survival of this culturally important population