Numerous genes expressed by intestinal epithelial cells are developmentally regulated, and the influence that adaptive (AI) and passive (PI) immunity have in controlling their expression has not been evaluated. In this study, we tested the hypothesis that both PI and AI influenced enterocyte gene expression by developing a breeding scheme that used T and B cell-deficient recombination-activating gene (RAG) mice. RNA was isolated from the liver and proximal/distal small intestine at various ages, and the steady-state levels of six different transcripts were evaluated by RNase protection assay. In wild-type (WT) pups, all transcripts [Fc receptor of the neonate (FcRn), polymeric IgA receptor (pIgR), GLUT5, lactase-phlorizin hydrolase (lactase), apical sodium-dependent bile acid transporter (ASBT), and Na+/glucose cotransporter (SGLT1)] studied were developmentally regulated at the time of weaning, and all transcripts except ASBT had the highest levels of expression in the proximal small intestine. In WT suckling pups reared in the absence of PI, pIgR mRNA levels were increased 100% during the early phase of development. In mice lacking AI, the expression of pIgR and lactase were significantly attenuated, whereas FcRn and GLUT5 levels were higher compared with WT mice. Finally, in the absence of both passive and active immunity, expression levels of pIgR and lactase were significantly lower than similarly aged WT mice. In summary, we report that the adaptive and passive immune status of mice influences steady-state mRNA levels of several important, developmentally regulated enterocyte genes during the suckling and weaning periods of life.

The microflorae in the intestine of breast-fed infants are distinct from those that typically populate the intestine of formula-fed infants. Although the acquisition of passive immunity through breast-feeding may play a critical role in influencing the pattern of bacterial colonization of the gut, the precise mechanisms underlying the differences in the commensal microflorae of breast and formula-fed children have not been established. We hypothesized that the assemblage of commensal microflorae in suckling and weaned mice may be influenced by the maternal adaptive immune system. To test this hypothesis, we analyzed the intestinal microflorae of mice reared in the presence (wild-type) or absence of an intact maternal immune system (T- and B-cell deficient). Several types of bacteria (Lactobacillus, Enterococcus, Clostridium perfringens, Bifidobacterium, and Bacteroides) were isolated and enumerated from both the small and large intestine of 10-, 18-, 25- and 40- to 60-d old mice using selective media. The densities of bacteria were significantly lower in the small intestine of weaned mice that were reared by wild-type (WT) compared with immunodeficient (ID) dams. However, the microflorae were generally more abundant in the large intestine of suckling pups reared by WT compared with ID dams. Our results indicate that intestinal microflorae change throughout the suckling phase of development and that the maternal adaptive immune system influences the pattern and abundance of bacteria within the gut in an age- and site-specific manner.

Cyclic Prefix Direct Sequence Spread Spectrum (CP-DSSS) is a novel waveform that is proposed as a solution to massive machine type communications (mMTC) for 5G and beyond. This paper analyzes the capacity of CP-DSSS in comparison with Orthogonal Frequency-Division Multiplexing (OFDM). We show that CP-DSSS achieves the same capacity as OFDM and can be optimized with similar precoding methods (e.g., water-filling). Because of its spread spectrum nature, CP-DSSS can operate as secondary network using the same spectrum as the primary 4G or 5G network, but transmitting at much lower power. Accordingly, the combination of primary and secondary signals in the envisioned setup may be viewed as a power NOMA (non-orthogonal multiple access) technique where primary signals are detected and subtracted from the received signal first before detecting the secondary signals. In order to operate at a sufficiently low interference level to the primary network, details of CP-DSSS capacity for symbol rate reduction and multi-antenna operation are developed. The capacity limits established in this paper can be used as a baseline to evaluate the performance of future CP-DSSS receiver architectures for single-and multi-user scenarios. I. INTRODUCTIONCyclic prefix direct sequence spread spectrum (CP-DSSS) is a novel waveform that was originally proposed as a solution to ultra-reliable low latency communication (URLLC) [1]-[3]. These references introduced CP-DSSS as a signaling method for sending a small number of information/control bits within each OFDM symbol interval concurrent with other network communication signals.CP-DSSS can also be used as a multi-user data channel to achieve massive machine type communication (mMTC) network density objectives as explored in [4] and [5]. Unlike URLLC, which is concerned largely with latency, probability of detection, and supporting packet formats, mMTC endeavors to support a massive number of low-cost and lowpower terminals. As low-cost and low-power transceivers are designed, it is important to compare their performance to the theoretical bounds. This paper presents a capacity analysis of CP-DSSS for a point-to-point link and establishes the peak per-user capacity, assuming an ideal receiver. Although the developed results are applicable to any signal-to-noise (SNR) ratio, the emphasis of this paper is on the low SNR regime

Obesity disproportionately affects women, especially those of African descent, and is associated with increases in both fat and muscle masses. Although increased extremity muscle mass may be compensatory to fat mass load, we propose that elevated insulin levels resulting from diminished insulin sensitivity may additionally contribute to extremity muscle mass in overweight or obese women. The following measurements were performed in 197 non-diabetic women (57% black, 35% white; age 46±11 years [mean±SD], BMI range 25.0 to 57.7 kg/m2): dual-energy X-ray absorptiometry for fat and extremity muscle masses; exercise performance by duration and peak oxygen consumption (VO2 peak) during graded treadmill exercise; fasting insulin and in 183 subjects insulin sensitivity index (SI) calculated from the minimal model. SI (range 0.5 to 14.1 liter/mU−1•min−1) was negatively, and fasting insulin (range 1.9 to 35.6 μU/mL) positively, associated with extremity muscle mass (both P<0.001), independent of age and height. Sixty-seven percent of women completed 6 months of participation in a weight loss and exercise program: We found a significant association between reduction in fasting insulin and a decrease in extremity muscle mass (P=0.038), independent of reduction in fat mass or improvement in exercise performance by VO2 peak and exercise duration, and without association with change in SI or interaction by race. Thus, hyperinsulinemia in overweight or obese women is associated with increased extremity muscle mass, which is partially reversible with reduction in fasting insulin concentration, consistent with stimulatory effects of insulin on skeletal muscle.