•Performance of ventilated wall with passive and BIPV façade is numerically compared.•Impact of thermal mass, cavity thickness, and its surface emissivity are studied.•BIPV façade could shift the ...heatwave amplitude up to 2 h.•Time lag in the BIPV structure could become 50% higher than the passive wall assembly.
Well-designed ventilated air-spaces behind external claddings in the building envelope can potentially reduce thermal energy flow in the entire wall structure. In this study, the impact of the dynamic thermo-hydraulic behavior of the flow in the naturally ventilated cavity on the performance of lightweight and heavyweight wall assemblies with traditional passive and active (i.e., BIPV) facades is investigated. A numerical transient 2-D model validated against experimental measurements is employed to perform the analysis using actual weather data and building practices in Europe, particularly in Switzerland. The results reveal that the change in the external cladding type from the passive fiber cement to the active PV façade can increase the time lag of the wall structure up to 2 h in summer and decrease it up to 1 h in winter. The maximum difference between the amplitudes of the heat flux through the interior surface for a wall assembly with the lightweight wall core is 1.5 times higher compared to a heavyweight wall core. The results show that enlarging the cavity thickness behind external claddings from 45 mm to 110 mm can increase the heat flow through the cavity up to 1.5 times. It is also shown that reflective insulation on the cavity surface adjacent to the wall core could increase the cladding surface temperature by more than 30% compared to the case without reflective insulation. This research shows that replacing the passive cladding with an active façade could affect the performance of the entire wall assembly, which highlights the importance of analyzing the active ventilated wall structures to transition towards modern building skins.
The set‐up of comprehensive studies in life sciences involving a longitudinal dimension—as appears in time‐scale metabolomics—calls for the use of dimension reduction techniques for three‐way data ...structures (e.g., samples by variables by time points). For this purpose, a clustering around latent variables for three‐way data approach, CLV3W, has been proposed. CLV3W aims at both partitioning the variables into nonoverlapping clusters and estimating within each cluster a rank‐one Parafac model consisting of a latent component (resp. a weighting system) associated with the first mode (resp. third mode) and a vector of loadings reflecting the degree of closeness of each variable of the second mode to its cluster. In this paper, two constrained CLV3W models are discussed. First, a nonnegativity constraint is defined implying that clusters are composed of positively correlated variables. Second, it is proposed to constrain the weighting system to be the same for all clusters. These two constraints aim at providing more parsimonious models with configurations that are easier to interpret. The appropriateness of both constraints is evaluated in a simulation study and illustrated on two case studies pertaining to sensory evaluation and metabolomics data. Regarding the first case study, CLV3W yields the identification of two consumer segments together with one common emotional pleasantness dimension associated with coffee aromas. CLV3W analysis of human preterm breast milk metabolomics data provided three clusters of lipid species that are responsible for specific functions (i.e., milk fat globules membrane‐constituents, fatty acid oxidation‐products, lipid mediators as eicosanoids and endocannabinoids).
A clustering around latent variables for three‐way data (CLV3W) approach is presented. Constraints on the configuration aim at facilitating the interpretation of the CLV3W solutions. Nonnegativity constraint on loadings requires clusters with positively correlated variables only. Application of CLV3W to time‐scale metabolomics data provides a partitioning into consistent groups of bio‐markers.
Human milk is recommended for feeding preterm infants. The current pilot study aims to determine whether breast-milk lipidome had any impact on the early growth-pattern of preterm infants fed their ...own mother's milk. A prospective-monocentric-observational birth-cohort was established, enrolling 138 preterm infants, who received their own mother's breast-milk throughout hospital stay. All infants were ranked according to the change in weight
-score between birth and hospital discharge. Then, we selected infants who experienced "slower" (
= 15, -1.54 ± 0.42
-score) or "faster" (
= 11, -0.48 ± 0.19
-score) growth; as expected, although groups did not differ regarding gestational age, birth weight
-score was lower in the "faster-growth" group (0.56 ± 0.72 vs. -1.59 ± 0.96). Liquid chromatography-mass spectrometry lipidomic signatures combined with multivariate analyses made it possible to identify breast-milk lipid species that allowed clear-cut discrimination between groups. Validation of the selected biomarkers was performed using multidimensional statistical, false-discovery-rate and ROC (Receiver Operating Characteristic) tools. Breast-milk associated with faster growth contained more medium-chain saturated fatty acid and sphingomyelin, dihomo-γ-linolenic acid (DGLA)-containing phosphethanolamine, and less oleic acid-containing triglyceride and DGLA-oxylipin. The ability of such biomarkers to predict early-growth was validated in presence of confounding clinical factors but remains to be ascertained in larger cohort studies.
Arginine, an essential amino acid during the reproductive period, has been shown to enhance lactation performances in livestock. Whether it could help mothers with breastfeeding difficulties is not ...known.
This study aimed to determine whether dietary arginine supplementation would enhance milk production in rat dams nursing large 12-pup litters and, if so, what mechanisms are involved.
In 3 series of experiments, differing in dam killing timing, 59 primiparous, pregnant Sprague-Dawley rats (mean ± SD weight: 254 ± 24.7 g) were randomly assigned to receive either 1) an AIN-93G diet supplemented with l-arginine at 2.0% (ARG diet), through lactation and gestation (AGL group); 2) a control AIN-93G diet including at 3.5% an isonitrogenous mix of amino acids that are not essential for lactation (MA diet), during gestation and lactation (MA group); or 3) the MA diet during gestation and the ARG diet during lactation (AL group). Milk flow was measured using deuterated water enrichment between days 11 and 18. Plasma hormones and mammary expression of genes involved in lactation were measured using ELISA and qRT-PCR, respectively, at lactation days 12, 18, or 21 in the 3 experiments. Data were analyzed by ANOVA.
Dam food intake, pup weight gain, milk flow normalized to dam weight, and milk fat concentration were 17%, 9%, 20%, and 20% greater in the AGL group than in the MA group, respectively (P < 0.05). Genes involved in lipogenesis and lipid regulation were overexpressed ≤2.76-fold in the mammary gland of AGL dams compared with MA dams (P < 0.05) and plasma leptin concentration was 39% higher (P = 0.008). Milk flow and composition and mammary gene expression of the AL group did not differ from those of the MA group, whereas milk fat concentration and flow were 26% and 37% lower than in the AGL group, respectively.
Arginine supplementation during gestation and lactation enhances milk flow and mammary lipogenesis in rats nursing large litters.
The impact of variants of concern (VoC) on SARS-CoV-2 viral dynamics remains poorly understood and essentially relies on observational studies subject to various sorts of biases. In contrast, ...experimental models of infection constitute a powerful model to perform controlled comparisons of the viral dynamics observed with VoC and better quantify how VoC escape from the immune response. Here we used molecular and infectious viral load of 78 cynomolgus macaques to characterize in detail the effects of VoC on viral dynamics. We first developed a mathematical model that recapitulate the observed dynamics, and we found that the best model describing the data assumed a rapid antigen-dependent stimulation of the immune response leading to a rapid reduction of viral infectivity. When compared with the historical variant, all VoC except beta were associated with an escape from this immune response, and this effect was particularly sensitive for delta and omicron variant (p<10-6 for both). Interestingly, delta variant was associated with a 1.8-fold increased viral production rate (p = 0.046), while conversely omicron variant was associated with a 14-fold reduction in viral production rate (p<10-6). During a natural infection, our models predict that delta variant is associated with a higher peak viral RNA than omicron variant (7.6 log10 copies/mL 95% CI 6.8-8 for delta; 5.6 log10 copies/mL 95% CI 4.8-6.3 for omicron) while having similar peak infectious titers (3.7 log10 PFU/mL 95% CI 2.4-4.6 for delta; 2.8 log10 PFU/mL 95% CI 1.9-3.8 for omicron). These results provide a detailed picture of the effects of VoC on total and infectious viral load and may help understand some differences observed in the patterns of viral transmission of these viruses.
Abstract Objective Nutrition during fetal life and early childhood is thought to play a crucial role in the risk for developing metabolic syndrome and cardiovascular diseases in the future adult and ...branched-chain amino acids (BCAA) intake may play a role in the development of obesity. The aim of this study was to compare the breast milk amino acid profiles of obese and normal weight (control) breast-feeding mothers. Methods Fifty obese and 50 control breast-feeding mothers were enrolled. Age and parity were similar in both groups. Breast milk samples were collected at the end of the first month of lactation. Free amino acid (FAA) concentrations in breast milk were determined by ultra-performance liquid chromatography tandem mass spectrometry. Comparisons between groups were performed using a two-tailed paired t test. Results We analyzed 45 breast milk samples from each group. Body mass index was 34.3 ± 3.9 kg/m2 in the obese group and 21.6 ± 1.4 kg/m2 in the control group ( P < 10−4 ). BCAA concentrations were higher in breast milk of obese mothers (95.5 ± 38.2 μM versus 79.8 ± 30.9 μM; P = 0.037), as was tyrosine concentration (13.8 ± 7.1 μM versus 10.6 ± 5.2 μM; P = 0.016). Conclusion The mature breast milk of obese mothers contained 20% more BCAA and 30% more tyrosine than breast milk of control mothers. Whether altered breast milk FAA profile affects metabolic risk in the breast-fed child remains to be explored.
Milk composition is complex and includes numerous components essential for offspring growth and development. In addition to the high abundance of miR-30b microRNA, milk produced by the transgenic ...mouse model of miR-30b-mammary deregulation displays a significantly altered fatty acid profile. Moreover, wild-type adopted pups fed miR-30b milk present an early growth defect.
This study aimed to investigate the consequences of miR-30b milk feeding on the duodenal development of wild-type neonates, a prime target of suckled milk, along with comprehensive milk phenotyping.
The duodenums of wild-type pups fed miR-30b milk were extensively characterized at postnatal day (PND)-5, PND-6, and PND-15 using histological, transcriptomic, proteomic, and duodenal permeability analyses and compared with those of pups fed wild-type milk. Milk of miR-30b foster dams collected at mid-lactation was extensively analyzed using proteomic, metabolomic, and lipidomic approaches and hormonal immunoassays.
At PND-5, wild-type pups fed miR-30b milk showed maturation of their duodenum with 1.5-fold (P < 0.05) and 1.3-fold (P < 0.10) increased expression of Claudin-3 and Claudin-4, respectively, and changes in 8 duodenal proteins (P < 0.10), with an earlier reduction in paracellular and transcellular permeability (183 ng/mL fluorescein sulfonic acid FSA and 12 ng/mL horseradish peroxidase HRP, respectively, compared with 5700 ng/mL FSA and 90 ng/mL HRP in wild-type; P < 0.001). Compared with wild-type milk, miR-30b milk displayed an increase in total lipid (219 g/L compared with 151 g/L; P < 0.05), ceramide (17.6 μM compared with 6.9 μM; P < 0.05), and sphingomyelin concentrations (163.7 μM compared with 76.3 μM; P < 0.05); overexpression of 9 proteins involved in the gut barrier (P < 0.1); and higher insulin and leptin concentrations (1.88 ng/mL and 2.04 ng/mL, respectively, compared with 0.79 ng/mL and 1.06 ng/mL; P < 0.01).
miR-30b milk displays significant changes in bioactive components associated with neonatal duodenal integrity and maturation, which could be involved in the earlier intestinal closure phenotype of the wild-type pups associated with a lower growth rate.
Background
Feeding supplemented mother milk during hospital stay improves neurodevelopment in preterm infants. Yet the composition of mother milk varies widely between subjects. The relationship ...between this variation and outcome is unknown.
Objective
To determine whether the protein content in native breast milk (BM) correlates with 2-year infant outcome.
Design
In a monocentric prospective observational study, LACTACOL, preterm infants born between 28 and 34 weeks of gestation, whose mothers decided to exclusively breastfeed, were enrolled during the first week of life. Samples of expressed breast milk obtained at several times of the day were pooled over a 24-h period, and such pool was used for macronutrient analysis, using mid-infrared analyzer. Age and Stages questionnaire (ASQ) was used to assess 2-year neurodevelopmental outcome. We analyzed the relationship between protein content in BM, and (i) infant neurodevelopment at 2-year (primary outcome), and (ii) growth until 2-year (secondary outcome).
Results
138 infants were enrolled. The main analysis concerned 130 infants (including 40 twin infants) and 110 mothers with BM samples collected at week 3 after birth. Native BM samples were ranked in three tertiles of protein content (g/100 ml): 0.91 ± 0.09 (lower), 1.14 ± 0.05 (middle) and 1.40 ± 0.15 (upper); 48, 47 and 35 infants were ranked, respectively, in these three tertiles. Infants in the upper tertile were more often singleton (
P
= 0.012) and were born with lower birth weight and head circumference Z-scores (
P
= 0.005 and 0.002, respectively). Differences in weight and head circumference were no longer observed at 2-year. ASQ score at age 2 did not differ between the three tertiles (
P
= 0.780). Sensitivity analyses with imputations, including all 138 infants, confirmed the main analysis as well as analyses based on fortified BM as exposure.
Conclusions
Protein content of BM (native or fortified) is not associated with preterm infant neurodevelopment at 2-year. Higher protein content was associated with a lower birth weight.
Lactation is a critical period during which maternal sub- or over-nutrition affect milk composition and offspring development that can have lasting health effects. The consequences of moderate ...high-fat, high-simple carbohydrate diet (WD) consumption by rat dams, during gestation and lactation, on milk composition and offspring blood lipidome and its growth, at weaning, were investigated by using a comprehensive lipidomic study on mass-spectrometric platform combined to targeted fatty- and free amino-acids analysis. This holistic approach allowed clear-cut differences in mature milk-lipidomic signature according to maternal diet with a similar content of protein, lactose and leptin. The lower WD-milk content in total fat and triglycerides (TGs), particularly in TGs-with saturated medium-chain, and higher levels in both sphingolipid (SL) and TG species with unsaturated long-chain were associated to a specific offspring blood-lipidome with decreased levels in TGs-containing saturated fatty acid (FA). The sexual-dimorphism in the FA-distribution in TG (higher TGs-rich in oleic and linoleic acids, specifically in males) and SL species (increased levels in very long-chain ceramides, specifically in females) could be associated with some differences that we observed between males and females like a higher total body weight gain in females and an increased preference for fatty taste in males upon weaning.
Fenugreek, a herbal remedy, has long been used as galactologue to help mothers likely to stop breastfeeding because of perceived insufficient milk production. However, few studies highlight the ...efficacy of fenugreek in enhancing milk production. The aims of our study were to determine whether fenugreek increased milk yield in rodent models of lactation challenge and if so, to verify the lack of adverse effects on dam and offspring metabolism. Two lactation challenges were tested: increased litter size to 12 pups in dams fed a 20% protein diet and perinatal restriction to an 8% protein diet with eight pups' litter, with or without 1 g.kg
.day
dietary supplementation of fenugreek, compared to control dams fed 20% protein diet with eight pups' litters. Milk flow was measured by the deuterium oxide enrichment method, and milk composition was assessed. Lipid and glucose metabolism parameters were assessed in dam and offspring plasmas. Fenugreek increased milk production by 16% in the litter size increase challenge, resulting in an 11% increase in pup growth without deleterious effect on dam-litter metabolism. Fenugreek had no effect in the maternal protein restriction challenge. These results suggest a galactologue effect of fenugreek when mothers have no physiological difficulties in producing milk.
PDF
