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"Klein, Laura"
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Concentrations of trace elements in human milk: Comparisons among women in Argentina, Namibia, Poland, and the United States
Human milk contains essential micronutrients for growth and development during early life. Environmental pollutants, such as potentially toxic metals, can also be transferred to the infant through human milk. These elements have been well-studied, but changing diets and environments and advances in laboratory technology require re-examining these elements in a variety of settings. The aim of this study was to characterize the concentrations of essential and toxic metals in human milk from four diverse populations. Human milk samples (n = 70) were collected in Argentina (n = 21), Namibia (n = 6), Poland (n = 23), and the United States (n = 20) using a standardized mid-feed collection procedure. Milk concentrations of calcium, zinc, iron, copper, manganese, lead, arsenic, and cadmium were determined using inductively coupled plasma mass spectrometry (ICP-MS). We used standard multiple linear regression models to evaluate differences among populations, while including infant age, infant sex, and maternal parity status (multiparous or primiparous) as covariates. Concentrations of all elements, except zinc, varied across populations after controlling for infant age, infant sex, and maternal parity. Calcium and magnesium showed more differences across populations than iron or copper. There were no significant differences among population in zinc concentrations. Mean concentrations of lead, but not arsenic, were low compared to recently published values from other populations. The concentrations of trace elements in human milk are variable among populations. Limitations due to small sample sizes and environmental contamination of some samples prevent us from drawing robust conclusions about the causes of these differences.
Journal Article
Writing programs, collaborations, and partnerships : transcending boundaries
\"This book demonstrates how to develop and engage in successful academic collaborations that are both practical and sustainable across campuses and within local communities. Authored by experienced writing program administrators, this edited collection includes a wide range of information addressing collaborative partnerships and projects, theoretical explorations of collaborative praxis, and strategies for sustaining collaborative initiatives. Contributors offer case studies of writing program collaborations and honestly address both the challenges of academic collaboration and the hallmarks of successful partnerships.\"--Publisher description.
Book
Grapevine scion gene expression is driven by rootstock and environment interaction
Background
Grafting is a horticultural practice used widely across woody perennial crop species to fuse together the root and shoot system of two distinct genotypes, the rootstock and the scion, combining beneficial traits from both. In grapevine, grafting is used in nearly 80% of all commercial vines to optimize fruit quality, regulate vine vigor, and enhance biotic and abiotic stress-tolerance. Rootstocks have been shown to modulate elemental composition, metabolomic profiles, and the shape of leaves in the scion, among other traits. However, it is currently unclear how rootstock genotypes influence shoot system gene expression as previous work has reported complex and often contradictory findings.
Results
In the present study, we examine the influence of grafting on scion gene expression in leaves and reproductive tissues of grapevines growing under field conditions for three years. We show that the influence from the rootstock genotype is highly tissue and time dependent, manifesting only in leaves, primarily during a single year of our three-year study. Further, the degree of rootstock influence on scion gene expression is driven by interactions with the local environment.
Conclusions
Our results demonstrate that the role of rootstock genotype in modulating scion gene expression is not a consistent, unchanging effect, but rather an effect that varies over time in relation to local environmental conditions.
Journal Article
Glycerol 3-phosphate phosphatase/PGPH-2 counters metabolic stress and promotes healthy aging via a glycogen sensing-AMPK-HLH-30-autophagy axis in C. elegans
Metabolic stress caused by excess nutrients accelerates aging. We recently demonstrated that the newly discovered enzyme glycerol-3-phosphate phosphatase (G3PP; gene
Pgp
), which operates an evolutionarily conserved glycerol shunt that hydrolyzes glucose-derived glycerol-3-phosphate to glycerol, counters metabolic stress and promotes healthy aging in
C. elegans
. However, the mechanism whereby G3PP activation extends healthspan and lifespan, particularly under glucotoxicity, remained unknown. Here, we show that the overexpression of the
C. elegans
G3PP homolog, PGPH-2, decreases fat levels and mimics, in part, the beneficial effects of calorie restriction, particularly in glucotoxicity conditions, without reducing food intake. PGPH-2 overexpression depletes glycogen stores activating AMP-activate protein kinase, which leads to the HLH-30 nuclear translocation and activation of autophagy, promoting healthy aging. Transcriptomics reveal an HLH-30-dependent longevity and catabolic gene expression signature with PGPH-2 overexpression. Thus, G3PP overexpression activates three key longevity factors, AMPK, the TFEB homolog HLH-30, and autophagy, and may be an attractive target for age-related metabolic disorders linked to excess nutrients.
Activation of the glycerol shunt mimics calorie restriction, protects from glucotoxicity, and promotes healthy aging. Here, Possik et al. uncover the underlying mechanism and identify the AMPK-TFEB autophagy pathway as critical to the healthy aging phenotype.
Journal Article
Potential radiation dose reduction in clinical photon-counting CT by the small pixel effect: ultra-high resolution (UHR) acquisitions reconstructed to standard resolution
Objective
To assess the potential dose reduction achievable with clinical photon-counting CT (PCCT) in ultra-high resolution (UHR) mode compared to acquisitions using the standard resolution detector mode (Std).
Materials and methods
With smaller detector pixels, PCCT achieves far higher spatial resolution than energy-integrating (EI) CT systems. The reconstruction of UHR acquisitions to the lower spatial resolution of conventional systems results in an image noise and radiation dose reduction. We quantify this small pixel effect in measurements of semi-anthropomorphic abdominal phantoms of different sizes as well as in a porcine knuckle in the first clinical PCCT system by using the UHR mode (0.2 mm pixel size at isocenter) in comparison to the standard resolution mode (0.4 mm). At different slice thicknesses (0
.
4 up to 4 mm) and dose levels between 4 and 12 mGy, reconstructions using filtered backprojection were performed to the same target spatial resolution, i.e., same modulation transfer function, using both detector modes. Image noise and the resulting potential dose reduction was quantified as a figure of merit.
Results
Images acquired using the UHR mode yield lower noise in comparison to acquisitions using standard pixels at the same resolution and noise level. This holds for sharper convolution kernels at the spatial resolution limit of the standard mode, e.g., up to a factor 3.2 in noise reduction and a resulting potential dose reduction of up to almost 90%.
Conclusion
Using sharper convolution kernels, UHR acquisitions allow for a significant dose reduction compared to acquisitions using the standard detector mode.
Clinical relevance
Acquisitions should always be performed using the ultra-high resolution detector mode, if possible, to benefit from the intrinsic noise and dose reduction.
Key Points
•
Ionizing radiation used in computed tomography examinations is a concern to public health.
•
The ultra-high resolution of novel photon-counting systems can be invested towards a noise and dose reduction if only a spatial resolution below the resolution limit of the detector is desired
.
•
Acquisitions should always be performed in ultra-high resolution mode, if possible, to benefit from an intrinsic dose reduction.
Journal Article
Latent developmental and evolutionary shapes embedded within the grapevine leaf
Across plants, leaves exhibit profound diversity in shape. As a single leaf expands, its shape is in constant flux. Plants may also produce leaves with different shapes at successive nodes. In addition, leaf shape varies among individuals, populations and species as a result of evolutionary processes and environmental influences. Because leaf shape can vary in many different ways, theoretically, the effects of distinct developmental and evolutionary processes are separable, even within the shape of a single leaf. Here, we measured the shapes of > 3200 leaves representing > 270 vines from wild relatives of domesticated grape (Vitis spp.) to determine whether leaf shapes attributable to genetics and development are separable from each other. We isolated latent shapes (multivariate signatures that vary independently from each other) embedded within the overall shape of leaves. These latent shapes can predict developmental stages independent from species identity and vice versa. Shapes predictive of development were then used to stage leaves from 1200 varieties of domesticated grape (Vitis vinifera), revealing that changes in timing underlie leaf shape diversity. Our results indicate that distinct latent shapes combine to produce a composite morphology in leaves, and that developmental and evolutionary contributions to shape vary independently from each other.
Journal Article
Employee Cardiometabolic Risk Following a Cluster-Randomized Workplace Intervention From the Work, Family and Health Network, 2009–2013
Objectives. To examine whether workplace interventions to increase workplace flexibility and supervisor support and decrease work–family conflict can reduce cardiometabolic risk. Methods. We randomly assigned employees from information technology (n = 555) and long-term care (n = 973) industries in the United States to the Work, Family and Health Network intervention or usual practice (we collected the data 2009–2013). We calculated a validated cardiometabolic risk score (CRS) based on resting blood pressure, HbA 1c (glycated hemoglobin), HDL (high-density lipoprotein) and total cholesterol, height and weight (body mass index), and tobacco consumption. We compared changes in baseline CRS to 12-month follow-up. Results. There was no significant main effect on CRS associated with the intervention in either industry. However, significant interaction effects revealed that the intervention improved CRS at the 12-month follow-up among intervention participants in both industries with a higher baseline CRS. Age also moderated intervention effects: older employees had significantly larger reductions in CRS at 12 months than did younger employees. Conclusions. The intervention benefited employee health by reducing CRS equivalent to 5 to 10 years of age-related changes for those with a higher baseline CRS and for older employees. Trial Registration. ClinicalTrials.gov Identifier: NCT02050204. (Am J Public Health. 2023;113(12):1322–1331. https://doi.org/10.2105/AJPH.2023.307413 )
Journal Article
Testosterone Trajectories and Reference Ranges in a Large Longitudinal Sample of Male Adolescents
Pubertal dynamics plays an important role in physical and psychological development of children and adolescents. We aim to provide reference ranges of plasma testosterone in a large longitudinal sample. Furthermore, we describe a measure of testosterone trajectories during adolescence that can be used in future investigations of development.
We carried out longitudinal measurements of plasma testosterone in 2,216 samples obtained from 513 males (9 to 17 years of age) from the Avon Longitudinal Study of Parents and Children. We used integration of a model fitted to each participant's testosterone trajectory to calculate a measure of average exposure to testosterone over adolescence. We pooled these data with corresponding values reported in the literature to provide a reference range of testosterone levels in males between the ages of 6 and 19 years.
The average values of total testosterone in the ALSPAC sample range from 0.82 nmol/L (Standard Deviation [SD]: 0.09) at 9 years of age to 16.5 (SD: 2.65) nmol/L at 17 years of age; these values are congruent with other reports in the literature. The average exposure to testosterone is associated with different features of testosterone trajectories such as Peak Testosterone Change, Age at Peak Testosterone Change, and Testosterone at 17 years of age as well as the timing of the growth spurt during puberty.
The average exposure to testosterone is a useful measure for future investigations using testosterone trajectories to examine pubertal dynamics.
Journal Article
Evaluation of dietary habits and cooking confidence using virtual teaching kitchens for perimenopausal women
Background
The transition to menopause is a time when women are at increased risk for chronic and cardiovascular diseases, and weight gain. This study evaluates the efficacy of virtual teaching kitchen (TK) interventions on cooking confidence and consumption of a healthy diet in women over 45.
Methods
This teaching kitchen intervention is a synchronous online series of classes for perimenopausal women, with 45 min of live cooking and 15 min of nutrition discussion. From September 2020 through January 2022, participants completed online pre- post-intervention surveys addressing weight, eating habits, cooking confidence and self-efficacy. Analysis used paired samples t-test and Wilcoxon signed rank sum test for normally and non-normal distributed data respectively.
Results
Of the 609 unique participants, 269 women completed both pre and post surveys after attending classes. Participants self-reported a statistically significant decreased weight (p < 0.001), increased daily consumption of fruit/vegetables (p < 0.039), fish (p < 0.001) and beans (p < 0.005), and decreased daily consumption of red meat (p < 0.001), sugary beverages (p < 0.029) and white grains (p < 0.039). There was significant improvement in cooking self-efficacy and confidence.
Conclusions
Virtual teaching kitchens were effective in improving culinary and dietary habits among peri- and post-menopausal women. This early evidence suggests that teaching kitchens can effectively reach larger populations for healthy behavioral modification.
Trial Registration
Study obtained IRB exemption.
Journal Article