'Effects of dehydration on central blood pressure in young healthy adults'.

PURPOSE: Brachial blood pressure (BP) is the current gold standard for BP assessment; however, measures of pulse wave velocity (PWV) and central blood pressure (CBP) may contribute uniquely to assessment of cardiovascular health status. As of yet, standards for assessment of CBP and PWV have not addressed the impact of hydration status on proper measurement. To understand the impact of hydration, PWV and CBP should be measured in a euhydrated and hypohydrated state. METHODS: Forty-three young, healthy participants (21 ± 2 years) completed a dehydration protocol utilizing moderate aerobic activity until they lost 1%-2% of their body weight. PWV and CBP were measured before and following the dehydration protocol. Linear regression was utilized to assess change in hydration status and change in PWV and CBP. RESULTS: No significant relationships were observed between the change in hydration status (% body weight lost) and PWV (ß = 0.05, p = 0.78) or central diastolic BP (ß = -3.8, p = 0.10), however, a significant relationship was observed with central systolic BP (ß = -5.0, p = 0.03). DISCUSSION: In conclusion, the assessment of hydration status before measurement of CBP or PWV may not be necessary in young, healthy individuals.

Virus-Induced Heritable Gene Editing in Plants.

Gene editing using clustered, regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) nuclease is an excellent tool for assessing gene function in plants. However, delivery of CRISPR/Cas-editing components into plant cells is still a major bottleneck and requires tissue culture-based approaches and regeneration of plants. To overcome this limitation, several plant viral vectors have recently been engineered to deliver single-guide RNA (sgRNA) targets into SpCas9-expressing plants. Here, we describe an optimized, step-by-step protocol based on the tobacco rattle virus (TRV)-based vector system to deliver sgRNAs fused to mobile tRNA sequences for efficient heritable editing in Nicotiana benthamiana and Arabidopsis thaliana model systems. The protocol described here could be adopted to study the function of any gene of interest.

Calponin homology domain containing kinesin, KIS1, regulates chloroplast stromule formation and immunity.

Chloroplast morphology changes during immunity, giving rise to tubule-like structures known as stromules. Stromules extend along microtubules and anchor to actin filaments along nuclei to promote perinuclear chloroplast clustering. This facilitates the transport of defense molecules/proteins from chloroplasts to the nucleus. Evidence for a direct role for stromules in immunity is lacking since, currently, there are no known genes that regulate stromule biogenesis. We show that a calponin homology (CH) domain containing kinesin, KIS1 (kinesin required for inducing stromules 1), is required for stromule formation during TNL [TIR (Toll/Interleukin-1 receptor)-type nucleotide-binding leucine-rich repeat]-immune receptor-mediated immunity. Furthermore, KIS1 is required for TNL-mediated immunity to bacterial and viral pathogens. The microtubule-binding motor domain of KIS1 is required for stromule formation while the actin-binding, CH domain is required for perinuclear chloroplast clustering. We show that KIS1 functions through early immune signaling components, EDS1 and PAD4, with salicylic acid-induced stromules requiring KIS1. Thus, KIS1 represents a player in stromule biogenesis.

Beer, wine, and spirits differentially influence body composition in older white adults-a United Kingdom Biobank study.

BACKGROUND: Aging is characterized by body composition alterations, including increased visceral adiposity accumulation and bone loss. Alcohol consumption may partially drive these alterations, but findings are mixed. This study primarily aimed to investigate whether different alcohol types (beer/cider, red wine, white wine/Champagne, spirits) differentially associated with body composition. METHODS: The longitudinal UK Biobank study leveraged 1869 White participants (40-80 years; 59% male). Participants self-reported demographic, alcohol/dietary consumption, and lifestyle factors using a touchscreen questionnaire. Anthropometrics and serum for proteomics were collected. Body composition was obtained via dual-energy X-ray absorptiometry. Structural equation modeling was used to probe direct/indirect associations between alcohol types, cardiometabolic biomarkers, and body composition. RESULTS: Greater beer/spirit consumptions were associated with greater visceral adiposity (ß = 0.069, p < 0.001 and ß = 0.014, p < 0.001, respectively), which was driven by dyslipidemia and insulin resistance. In contrast, drinking more red wine was associated with less visceral adipose mass (ß = -0.023, p < 0.001), which was driven by reduced inflammation and elevated high-density lipoproteins. White wine consumption predicted greater bone density (ß = 0.051, p < 0.005). DISCUSSION: Beer/spirits may partially contribute to the "empty calorie" hypothesis related to adipogenesis, while red wine may help protect against adipogenesis due to anti-inflammatory/eulipidemic effects. Furthermore, white wine may benefit bone health in older White adults.1.

Parasite effectors target helper NLRs in plants to suppress immunity-related cell death.

Parasites target the plant immune system for successful colonization. A new study in PLOS Biology reveals that unrelated parasites have evolved effectors that specifically suppress the function of helper nucleotide-binding leucine-rich repeats (NLRs), explaining the complex plant-parasite coevolutionary dynamics.

High-resolution mapping of the Mov-1 locus in wheat by combining radiation hybrid (RH) and recombination-based mapping approaches.

KEY MESSAGE: This work reports a quick method that integrates RH mapping and genetic mapping to map the dominant Mov-1 locus to a 1.1-Mb physical interval with a small number of candidate genes. Bread wheat is an important crop for global human population. Identification of genes and alleles controlling agronomic traits is essential toward sustainably increasing crop production. The unique multi-ovary (MOV) trait in wheat holds potential for improving yields and is characterized by the formation of 2-3 grains per spikelet. The genetic basis of the multi-ovary trait is known to be monogenic and dominant in nature. Its precise mapping and functional characterization is critical to utilizing this trait in a feasible manner. Previous mapping efforts of the locus controlling multiple ovary/pistil formation in the hexaploid wheat have failed to produce a consensus for a particular chromosome. We describe a mapping strategy integrating radiation hybrid mapping and high-resolution genetic mapping to locate the chromosomal position of the Mov-1 locus in hexaploid wheat. We used RH mapping approach using a panel of 188 lines to map the Mov-1 locus in the terminal part of long arm of wheat chromosome 2D with a map resolution of 1.67 Mb/cR1500. Then using a genetic population of MOV × Synthetic wheat of F2 lines, we delineated the Mov-1 locus to a 1.1-Mb physical region with a small number of candidate genes. This demonstrates the value of this integrated strategy to mapping dominant genes in wheat.

Caldera resurgence during the 2018 eruption of Sierra Negra volcano, Galápagos Islands.

Recent large basaltic eruptions began after only minor surface uplift and seismicity, and resulted in caldera subsidence. In contrast, some eruptions at Galápagos Island volcanoes are preceded by prolonged, large amplitude uplift and elevated seismicity. These systems also display long-term intra-caldera uplift, or resurgence. However, a scarcity of observations has obscured the mechanisms underpinning such behaviour. Here we combine a unique multiparametric dataset to show how the 2018 eruption of Sierra Negra contributed to caldera resurgence. Magma supply to a shallow reservoir drove 6.5 m of pre-eruptive uplift and seismicity over thirteen years, including an Mw5.4 earthquake that triggered the eruption. Although co-eruptive magma withdrawal resulted in 8.5 m of subsidence, net uplift of the inner-caldera on a trapdoor fault resulted in 1.5 m of permanent resurgence. These observations reveal the importance of intra-caldera faulting in affecting resurgence, and the mechanisms of eruption in the absence of well-developed rift systems.

Walking in the Light: How History of Physical Activity, Sunlight, and Vitamin D Account for Body Fat-A UK Biobank Study.

OBJECTIVE: The high prevalence of vitamin D deficiency and obesity drives the need for successful strategies that elevate vitamin D levels, prevent adipogenesis, and stimulate lipolysis. This study provides a theoretical model to evaluate how physical activity (PA) and sunlight exposure influence serum vitamin D levels and regional adiposity. This study hypothesized a posteriori that sunlight is associated with undifferentiated visceral adiposity by increasing the ratio of brown to white adipose tissue. METHODS: Using 10-year longitudinal data, accelerometry, a sun-exposure questionnaire, and regional adiposity quantified by dual-energy x-ray absorptiometry imaging, a structural-equation mediation model of growth curves was constructed with a data-driven methodology. RESULTS: Sunlight and PA conjointly increased serum vitamin D. Changes in vitamin D levels partially mediated how sunlight and PA impacted adiposity in visceral and subcutaneous regions within a subjective PA model. In an objective PA model, vitamin D was a mediator for subcutaneous regions only. Interestingly, sunlight was associated with less adiposity in subcutaneous regions but greater adiposity in visceral regions. CONCLUSIONS: Sunlight and PA may increase vitamin D levels. For the first time, this study characterizes a positive association between sunlight and visceral adiposity. Further investigation and experimentation are necessary to clarify the physiological role of sunlight exposure on adipose tissue.

Validation of a Multielectrode Bioelectrical Impedance Analyzer With a Dual-Energy X-Ray Absorptiometer for the Assessment of Body Composition in Older Adults.

Changes in body composition are related to mobility, fall risk, and mortality, especially in older adults. Various devices and methods exist to measure body composition, but bioelectrical impedance analysis (BIA) has several advantages. The purpose of this study was to validate a common BIA device with a dual-energy X-ray absorptiometer (DXA) in older adults and develop prediction equations to improve the accuracy of the BIA measurements. The participants were 277 older adults (162 women and 115 men; age 73.9 ± 5.8 years) without a history of cancer and without a history of severe medical or mental conditions. Individuals fasted 12 hr before BIA and DXA measurement. The correlations between the two methods for appendicular lean mass (ALM), fat-free mass (FFM), and percentage body fat (%BF) were .86, .93, and .92, respectively, adjusting for age and sex. The mean percentage error (DXA-InBody) and mean absolute percentage error were -12% and 13% for ALM, -13% and 13% for FFM, and 16% and 17% for %BF. The prediction equations estimated ALM, FFM, and %BF; sex was coded as 1 for male and 0 for female: DXAALM=0.0673+(0.6732×BIAALM)+(2.33507×sex)+(0.13349×BMI),R2=.94; DXAFFM=0.72323+(0.72384×BIAFFM)+(3.675012×sex)+(0.2816×BMI),R2=.97; and DXA%BF=15.8896+(0.64694×BIA%BF) -(3.99945×sex)+(0.13824×BMI),R2=.91 Although highly correlated, BIA overestimated FFM, and ALM and underestimated %BF compared with DXA. An application of prediction equations eliminated the mean error and reduced the range of individual error across the sample. Prediction equations may improve BIA accuracy sufficiently to substitute for DXA in some cases.

Physical activity and sarcopenia in older adults.

BACKGROUND: Sarcopenia is prevalent in ever growing older adult populations. AIM: The aim of this study was to quantify the association between physical activity (PA), sedentary time (SED), cardiorespiratory fitness (CRF), and strength (STR) with sarcopenia in community-dwelling older adults using a standard definition of sarcopenia. METHOD: This cross-sectional study examined a large group of older adults (n = 304) who provided a broad range of health, lifestyle, and socioeconomic variables. PA was assessed using a pedometer worn for 7 days. SED was assessed by survey. CRF was assessed by 400-m walk test performance. Strength (STR) was assessed by one-repetition maximum chest and leg press. The European Working Group on Sarcopenia in Older People (EWGSOP) definition defined 10.9% (n = 33) as sarcopenic. RESULTS: PA, CRF, and STR were significantly associated with sarcopenia components (muscle mass, muscle strength, and muscle function). The upper two-thirds of CRF had significantly lower odds of having sarcopenia, whereas the strongest third of STR was associated with lower odds of sarcopenia. All exposure variables had significant odds ratios associated with at least one component of sarcopenia. Joint analyses indicated additional benefit may be gained from being both active (≥ 5000 daily steps) and fit (top two-thirds), active and strong (top two-thirds), and fit and strong. DISCUSSION: Overall, objectively measured PA, CRF, and STR, and self-reported SED, are associated with sarcopenia and its components. CONCLUSION: Therefore, older adults who are physically active, maintain higher levels of cardiorespiratory fitness, upper and lower body strength, and avoid sedentary time may have significantly lower odds of sarcopenia.

Perspectives on intracellular perception of plant viruses.

The intracellular nucleotide-binding domain leucine-rich repeat (NLR) class of immune receptors plays an important role in plant viral defence. Plant NLRs recognize viruses through direct or indirect association of viral proteins, triggering a downstream defence response to prevent viral proliferation and movement within the plant. This review focuses on current knowledge of intracellular perception of viral pathogens, activation of NLRs and the downstream signalling components involved in plant viral defence.

Physical Activity, Cardiorespiratory Fitness, and Incident Glaucoma.

PURPOSE: This study aimed to examine the associations of physical activity and cardiorespiratory fitness (hereafter fitness) with incident glaucoma in a prospective observational study. METHODS: Physical activity was measured by self-reported leisure-time activities, and fitness was measured by maximal treadmill test. Incident glaucoma was defined based on physician diagnosis. Participants were 9519 men and women between the ages of 40 and 81 yr old (mean age 50 yr) who were enrolled in the Aerobics Center Longitudinal Study. Hazard ratios (HR) were estimated using Cox proportional hazard regression after adjusting for age, sex, race, examination year, smoking status, heavy alcohol drinking, hypertension, hypercholesterolemia, abnormal ECG, diabetes, cardiovascular disease, and cancer. RESULTS: A total of 128 cases of incident glaucoma were reported during a mean follow-up of 5.7 yr. A significantly lower risk of incident glaucoma (HR = 0.53, 95% confidence interval [95% CI] = 0.35-0.79) was found in individuals who met the physical activity guidelines of ≥500 MET·min·wk compared with inactive individuals (0 MET·min·wk). Compared with low fitness (lower third), individuals with high fitness (upper third) also had a significantly lower risk of incident glaucoma (HR = 0.60, 95% CI = 0.38-0.95). A joint analysis of physical activity and fitness showed that meeting physical activity guidelines and being in the high fitness category was associated with the lowest risk for developing glaucoma (HR = 0.49, 95% CI = 0.31-0.79). CONCLUSION: These data provide epidemiological evidence that meeting physical activity guidelines or being fit reduces the risk of developing glaucoma.

Comparison of Consumer and Research Monitors under Semistructured Settings.

PURPOSE: This study evaluated the relative validity of different consumer and research activity monitors during semistructured periods of sedentary activity, aerobic exercise, and resistance exercise. METHODS: Fifty-two (28 male and 24 female) participants age 18-65 yr performed 20 min of self-selected sedentary activity, 25 min of aerobic exercise, and 25 min of resistance exercise, with 5 min of rest between each activity. Each participant wore five wrist-worn consumer monitors [Fitbit Flex, Jawbone Up24, Misfit Shine (MS), Nike+ Fuelband SE (NFS), and Polar Loop] and two research monitors [ActiGraph GT3X+ on the waist and BodyMedia Core (BMC) on the arm] while being concurrently monitored with Oxycon Mobile (OM), a portable metabolic measuring system. Energy expenditure (EE) on different activity sessions was measured by OM and estimated by all monitors. RESULTS: Mean absolute percent error (MAPE) values for the full 80-min protocol ranged from 15.3% (BMC) to 30.4% (MS). EE estimates from ActiGraph GT3X+ were found to be equivalent to those from OM (± 10% equivalence zone, 285.1-348.5). Correlations between OM and the various monitors were generally high (ranged between 0.71 and 0.90). Three monitors had MAPE values lower than 20% for sedentary activity: BMC (15.7%), MS (18.2%), and NFS (20.0%). Two monitors had MAPE values lower than 20% for aerobic exercise: BMC (17.2%) and NFS (18.5%). None of the monitors had MAPE values lower than 25% for resistance exercise. CONCLUSION: Overall, the research monitors and Fitbit Flex, Jawbone Up24, and NFS provided reasonably accurate total EE estimates at the individual level. However, larger error was evident for individual activities, especially resistance exercise. Further research is needed to examine these monitors across various activities and intensities as well as under real-world conditions.

Walking versus biofeedback: a comparison of acute interventions for stressed students.

BACKGROUND: High rates of stress-related problems in college students and low utilization of treatment options demonstrate the need for effective stress-reducing interventions that can be self-regulated. This study compared the effect of brief paced-breathing with biofeedback and exercise interventions on heart rate variability, state anxiety and affect. METHODS: Students (n = 32) with high levels of perceived stress completed three 10-min interventions on separate days: paced-breathing with biofeedback (Biofeedback), a self-paced walk (Exercise), and an attention control condition of quiet studying (Quiet Study). Anxiety and affect were measured before (Pre), immediately after (Post0) and 15 mins after (Post15) the intervention. Heart rate variability was measured pre- and post-intervention using electrocardiogram. RESULTS: Biofeedback reduced anxiety more than the exercise condition (Pre to Post0: Biofeedback d = -0.48, Exercise d = -0.13). Secondly, Exercise temporarily increased energy (Pre to Post0: d = 0.67), whereas Biofeedback temporarily increased calmness (Pre to Post0: d = 0.51). All conditions significantly increased total heart rate variability (p < .05). CONCLUSIONS: Biofeedback and Exercise interventions improved emotional states in high-stress college students, but the type of change observed (i.e. energizing, calming or anxiety reducing) depended upon the condition.