Predictors of Weight Change in Middle‐aged and Old Men

Objective: Studies on weight change and mortality have yielded inconclusive results. This 10‐year prospective study was undertaken to improve understanding of factors affecting weight change. Research Methods and Procedures: The subjects were 1143 men, aged 36 to 88 years (mean, 53.3 years) at entry. A questionnaire was filled in at entry and at the end of the follow‐up with queries on weight, height, weight at the age of 20, physician‐diagnosed diseases, smoking, alcohol use, dietary habits, leisure physical activity, occupation, present occupational activity, living conditions (living alone or cohabiting), and former athletic status. Further information on morbidity was obtained from selected national registers. Factors predicting weight change during the study were identified by stepwise linear multiple regression analysis. Results: The mean 10‐year weight change was 0.8 (range, ?29 to +24) kg. Age at entry (β‐coefficient, ?0.17, SE 0.02), weight at entry (β, ?0.03, SE 0.01), diabetes at entry (β, ?3.55, SE 1.02), diabetes diagnosed after entry (β, ?3.94, SE 0.96), malignant cancer (β, ?1.60, SE 0.70), being a smoker (β, ?1.59, SE 0.48), and increased physical activity (β, ?1.27, SE 0.54) were significantly (p < 0.05) associated with weight loss in the final model. The model explained 13% of the variance of weight change. Discussion: The results emphasize the complexity of weight change. Some factors associated with weight change are apparently negatively, and some positively, associated with health. This could explain the equivocal findings on weight change and mortality in the literature.     

Expected early genetic gain from selection for milk yield in dairy cattle

Summary A matrix program to predict short term genetic gain from single trait selection for milk yield was developed. Rate of genetic gain was calculated as the annual change in the mean breeding value of all producing females. Several parameters sets representing various selection policies were used to examine situations pertinent to dairy populations of the United States. Approach to the asymptotic rates of genetic gain within the model varied with the choice of parameters, but even with consistent selection policies, predicted total genetic gain in the first 10 years was only half of the expected from classical theory. Considerable year to year variation in the rate of gain occurred. Early gains were more dependent on female selection decisions than gains during the steady state. In a two-phase model, the approach to the linear rate of gain in the second phase was accelerated by starting with an ongoing improvement program, but considerable delays still existed. Selection for sex- limited traits such as milk yield, which require pedigree selection and a waiting time for progeny test results reached asymptotic rates more slowly than previously assumed.     

Phosphoproteome Profiling of the Receptor Tyrosine Kinase MuSK Identifies Tyrosine Phosphorylation of Rab GTPases

Muscle-specific receptor tyrosine kinase (MuSK) agonist antibodies were developed 2 decades ago to explore the benefits of receptor activation at the neuromuscular junction. Unlike agrin, the endogenous agonist of MuSK, agonist antibodies function independently of its coreceptor low-density lipoprotein receptor–related protein 4 to delay the onset of muscle denervation in mouse models of ALS. Here, we performed dose–response and time-course experiments on myotubes to systematically compare site-specific phosphorylation downstream of each agonist. Remarkably, both agonists elicited similar intracellular responses at known and newly identified MuSK signaling components. Among these was inducible tyrosine phosphorylation of multiple Rab GTPases that was blocked by MuSK inhibition. Importantly, mutation of this site in Rab10 disrupts association with its effector proteins, molecule interacting with CasL 1/3. Together, these data provide in-depth characterization of MuSK signaling, describe two novel MuSK inhibitors, and expose phosphorylation of Rab GTPases downstream of receptor tyrosine kinase activation in myotubes.     

An Improved Boosting to Amplify Signal with Isobaric Labeling (iBASIL) Strategy for Precise Quantitative Single-cell Proteomics

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Highlights

• •Higher AGC significantly improves quantitation quality in single-cell analysis.
• •The boosting-to-sample ratio should be carefully evaluated and optimized.
• •iBASIL allows for precise quantitation of 1,500 proteins from 104 AML single cells.
• •iBASIL recapitulates major biological differences in different AML single cells.

     

Hydraulic acclimation in a Mediterranean oak subjected to permanent throughfall exclusion results in increased stem hydraulic capacitance

Stem water storage capacity and hydraulic capacitance (C_S) play a crucial role in tree survival under drought-stress. To investigate whether C_S adjusts to increasing water deficit, variation in stem water content (StWC) was monitored in vivo for 2 years and related to periodical measurements of tree water potential in Mediterranean Quercus ilex trees subjected either to permanent throughfall exclusion (TE) or to control conditions. Seasonal reductions in StWC were larger in TE trees relative to control ones, resulting in greater seasonal C_S (154 and 80 kg m⁻³ MPa⁻¹, respectively), but only during the first phase of the desorption curve, when predawn water potential was above −1.1 MPa. Below this point, C_S decreased substantially and did not differ between treatments (<20 kg m⁻³ MPa⁻¹). The allometric relationship between tree diameter and sapwood area, measured via electrical resistivity tomography, was not affected by TE. Our results suggest that (a) C_S response to water deficit in the drought-tolerant Q. ilex might be more important to optimize carbon gain during well-hydrated periods than to prevent drought-induced embolism formation during severe drought stress, and (b) enhanced C_S during early summer does not result from proportional increases in sapwood volume, but mostly from increased elastic water.     

A meta-analysis of nutrient intake,feed efficiency and performance in cattle grazing on tropical grasslands

It is essential to quantify the potential of tropical grasslands to allow significant feed efficiency for grazing livestock in controlled conditions such as at pasture. We conducted a quantitative analysis of published studies reporting the experimental results of average daily gains (ADG) and diet characteristics obtained specifically under grazing conditions (17 publications and 41 experiments), which have been less studied compared with controlled conditions in stalls. The database was analyzed to determine the average and range of values obtained for ADG (g/kg BW), dry matter digestibility, intake (DMI) and digestible DMI (DDMI, g/kg BW) and feed conversion efficiencies (FCE), as well as to predict the response of these parameters to the main strategies investigated in the literature – that is, mainly the stocking rate (SR) and the concentrate intake (CI). The ADG reached 1.2 kg BW per day and was directly linked to DDMI (ADG=−1.63+0.42 DDMI −0.0084 DDMI², n=90, r.m.s.e=0.584, R²=0.93). The DDMI, which was representative of the nutrient input, was driven mainly by DMI rather than dry matter digestibility, whereas these two parameters did not correlate (r=0.068, P=0.56). The average global FCE (0.11 g ADG/g DDMI) showed a greater association with the metabolic FCE (0.17 g ADG/g DMI) than the digestive FCE (0.62). The CI (g DM/kg BW) increased ADG (ADG=2376+CI 56.1, n=16, r.m.s.e.=441, R²=0.95). The SR expressed as kg BW/ha decreased the individual ADG by 1.19 g/kg BW per additional ton of BW/ha, whereas the global ADG calculated per ha increased by 0.57 per additional ton BW/ha. When the SR was expressed as kg BW/ton DM and per ha rather than as kg BW/ha, the impact on the individual ADG decreased by 0.18 or 0.86 g per additional ton BW/ha, depending on the initial BW of the cattle. These results provide a better view of the potential performance and feeding of cattle in tropical grasslands. The results provide an improved quantification of the relationships between diet and performance, as well as the overall quantitative impact of SR and supplementation.     

Unpacking chimpanzee (Pan troglodytes) patch use: Do individuals respond to food patches as predicted by the marginal value theorem?

The marginal value theorem is an optimal foraging model that predicts how efficient foragers should respond to both their ecological and social environments when foraging in food patches, and it has strongly influenced hypotheses for primate behavior. Nevertheless, experimental tests of the marginal value theorem have been rare in primates and observational studies have provided conflicting support. As a step towards filling this gap, we test whether the foraging decisions of captive chimpanzees (Pan troglodytes) adhere to the assumptions and qualitative predictions of the marginal value theorem. We presented 12 adult chimpanzees with a two-patch foraging environment consisting of both low-quality (i.e., low-food density) and high-quality (i.e., high-food density) patches and examined the effect of patch quality on their search behavior, foraging duration, marginal capture rate, and its proxy measures: giving-up density and giving-up time. Chimpanzees foraged longer in high-quality patches, as predicted. In contrast to predictions, they did not depress high-quality patches as thoroughly as low-quality patches. Furthermore, since chimpanzees searched in a manner that fell between systematic and random, their intake rates did not decline at a steady rate over time, especially in high-quality patches, violating an assumption of the marginal value theorem. Our study provides evidence that chimpanzees are sensitive to their rate of energy intake and that their foraging durations correlate with patch quality, supporting many assumptions underlying primate foraging and social behavior. However, our results question whether the marginal value theorem is a constructive model of chimpanzee foraging behavior, and we suggest a Bayesian foraging framework (i.e., combining past foraging experiences with current patch sampling information) as a potential alternative. More work is needed to build an understanding of the proximate mechanisms underlying primate foraging decisions, especially in more complex socioecological environments.     

Growth performance,haematological assessment and chemical composition of Nile tilapia,Oreochromis niloticus (Linnaeus, 1758) fed different levels of Aloe vera extract as feed additives in a closed aquaculture system

A 105-day experimental trial was conducted to assess different levels of dietary Aleo vera extract supplementation on water quality parameters, proximate composition, growth performance and haematological parameters of fry Oreochromis niloticus. Four different percentages of dietary leaf extract powder of Aleo vera (ALE) with a basal feed, designated as, i.e., T0 (Control group; without ALE), T1 (1% ALE), T2 (2% ALE), and T3 (3% ALE). Fish fry was reared in concrete tanks (7.0 m, 1.6 m, 1.0: L, W, H; water volume 11.2 m3/tank), with an average initial weight 4.04 ± 0.03 g/ fry, and each treatment was triplicated. Fry was randomly distributed at a stocking rate of 450 individuals/ tanks. The water quality parameters revealed that temperature, pH, salinity, dissolved oxygen (DO) and nitrates were found in a promising range as given by FAO/WHO limits. However, the record values obtained for Electric Conductivity (EC), Total dissolved solids (TDS), and alkalinities were not found in all tanks' suitable range according to FAO/WHO limits. The results revealed a significant impact of different percentages of dietary ALE supplementation on fry's body composition and haematological parameters. Moreover, the final body weight, final body length, average daily weight gain (g), net weight gain (g) and specific growth rate (%) were significantly higher (p < 0.05) in T1 and T2 compared with T0 and T3 treatments. The poorest feed conversion ratio was recorded in the T2 group compared with other treatments. Thus, the current study provides information about the nutritional quality of Nile tilapia culturing in Pakistan.     

Mass Spectrometry–Driven Discovery of Neuropeptides Mediating Nictation Behavior of Nematodes

Neuropeptides regulate animal physiology and behavior, making them widely studied targets of functional genetics research. While the field often relies on differential -omics approaches to build hypotheses, no such method exists for neuropeptidomics. It would nonetheless be valuable for studying behaviors suspected to be regulated by neuropeptides, especially when little information is otherwise available. This includes nictation, a phoretic strategy of Caenorhabditis elegans dauers that parallels host-finding strategies of infective juveniles of many pathogenic nematodes. We here developed a targeted peptidomics method for the model organism C. elegans and show that 161 quantified neuropeptides are more abundant in its dauer stage compared with L3 juveniles. Many of these have orthologs in the commercially relevant pathogenic nematode Steinernema carpocapsae, in whose infective juveniles, we identified 126 neuropeptides in total. Through further behavioral genetics experiments, we identify flp-7 and flp-11 as novel regulators of nictation. Our work advances knowledge on the genetics of nictation behavior and adds comparative neuropeptidomics as a tool to functional genetics workflows.