Pleistocene Terraces of The Atlantic Coastal Plain

Pleistocene terraces on the Atlantic Coastal Plain have been recognized since the late 1800\u27s, and from four to seven terraces have been described throughout Maryland, Virginia, North Carolina, South Carolina, and Florida. These terraces are now named Brandywine, Coharie, Sunderland, Wicomico, Penholoway, Talbot or Chowan, and Pamlico; and they are defined by relatively concordant shorelines at altitudes of 270-, 215-, 170-, 100-, 70-, 42-, and 25 feet above sea level. They have been correlated with respect to the glacial ages and substages and corresponding eustatic changes in sea level. The Various hypotheses regarding the origin of the terraces are: 1. Marine, with a cycle of marine deposition, uplift and erosion, and submergence with a continuous fall of sea level: 2. A dominantly fluvial origin; and 3. A combination fluvial-marine origin. No one hypothesis has been accepted completely, although the second marine hypothesis and the fluvial hypothesis have had more support than any other

A review of the immunomodulating components of maternal breast milk and protection against necrotizing enterocolitis

Breast milk contains immunomodulating components that are beneficial to newborns during maturation of their immune system. Human breast milk composition is influenced by an infant\u27s gestational and chronological age, lactation stage, and the mother and infant\u27s health status. Major immunologic components in human milk, such as secretory immunoglobulin A (IgA) and growth factors, have a known role in regulating gut barrier integrity and microbial colonization, which therefore protect against the development of a life-threatening gastrointestinal illness affecting newborn infants called necrotizing enterocolitis (NEC). Breast milk is a known protective factor in the prevention of NEC when compared with feeding with commercial formula. Breast milk supplements infants with human milk oligosaccharides, leukocytes, cytokines, nitric oxide, and growth factors that attenuate inflammatory responses and provide immunological defenses to reduce the incidence of NEC. This article aims to review the variety of immunomodulating components in breast milk that protect the infant from the development of NEC

Neutrino masses from discrete gauge symmetries

We investigate a model with an extra $Z_{2}$ gauge symmetry in the Standard Model. We assume that only the scalars and the leptons carry non-zero charge. The symmetry gives a structure to the mass matrix for the neutrinos. With two extra Higgs singlets and two extra singlet right-handed neutrinos we can build a model that fits the requirements of the MSW-solution of the Solar neutrino problem. With a third singlet right-handed neutrino it is also possible to have a 10 eV neutrino, a dark matter candidate.Comment: SNUTP 92-105, Late

Fire behaviour in a semi-arid Baikiaea plurijuga savanna woodland on Kalahari sands in western Zimbabwe

Human-induced fires are a major disturbance in Baikiaea plurijuga woodland savannas that are economically important for timber production. Most fires occur during the late dry season, when they may severely damage woody plants. Prescribed burning during the early dry season is a management strategy to reduce fuel loads and thus the incidence of intense fires during the late dry season. There is, however, little information on fire behaviour characteristics of early dry season fires.We studied the relationship between experimental fuel conditions and fire behaviour by lighting 15 fires during the early dry season in a Baikiaea woodland. Fire intensity ranged from 25 to 1341 kW m[superscript (-1)], while rate of spread of fire varied between 0.01 and 0.35ms[superscript (-1)]. Fire intensity and rate of spread were positively related to flame height, leaf-scorch height and proportion of the area burnt. The relationships suggest that fire characteristics can be retrospectively determined using a variable such as scorch height. The grass fuel load, wind speed, relative humidity and to a lesser extent fuel moisture were important predictors of rate of spread, flame height, leaf-scorch height and proportion of the area burnt, with no impact due to the litter fuel load. The grass fuel load and wind speed had a positive effect on rate of spread, whereas relative humidity and fuel moisture had a negative effect. These findings indicate that managers can predict the likely damage to woody plants during an early dry season burn by assessing the grass fuel load and weather conditions at the time of burning

Two-sided heterogeneity and trade

This paper develops a multi-country model of international trade that provides a simple microfoundation for buyer-seller relationships in trade. We explore a rich dataset that identifies buyers and sellers in trade and establish a set of basic facts that guide the development of the theoretical model. We use predictions of the model to examine the role of buyer heterogeneity in a market for firm-level adjustments to trade shocks, as well as to quantitatively evaluate how firms’ marginal costs depend on access to suppliers in foreign markets

An Empirical Investigation of Pull Requests in Partially Distributed BizDevOps Teams

In globally distributed projects, virtual teams are often partially dispersed. One common setup occurs when several members from one company work with a large outsourcing vendor based in another country. Further, the introduction of the popular BizDevOps concept has increased the necessity to cooperate across departments and reduce the age-old disconnection between the business strategy and technical development. Establishing a good collaboration in partially distributed BizDevOps teams requires extensive collaboration and communication techniques. Nowadays, a common approach is to rely on collaboration through pull requests and frequent communication on Slack. To investigate barriers for pull requests in distributed teams, we examined an organization located in Scandinavia where cross-functional BizDevOps teams collaborated with off-site team members in India. Data were collected by conducting 14 interviews, observing 23 entire days with the team, and observing 37 meetings. We found that the pull-request approach worked very well locally but not across sites. We found barriers such as domain complexity, different agile processes (timeboxed vs. flow-based development), and employee turnover. Using an intellectual capital lens on our findings, we discuss barriers and positive and negative effects on the success of the pull-request approach

A conservative, optimization-based semi-lagrangian spectral element method for passive tracer transport

We present a new optimization-based, conservative, and quasi-monotone method for passive tracer transport. The scheme combines high-order spectral element discretization in space with semi-Lagrangian time stepping. Solution of a singly linearly constrained quadratic program with simple bounds enforces conservation and physically motivated solution bounds. The scheme can handle efficiently a large number of passive tracers because the semi-Lagrangian time stepping only needs to evolve the grid points where the primitive variables are stored and allows for larger time steps than a conventional explicit spectral element method. Numerical examples show that the use of optimization to enforce physical properties does not affect significantly the spectral accuracy for smooth solutions. Performance studies reveal the benefits of high-order approximations, including for discontinuous solutions

Experimental verification of parameters in automobile crankshaft modelling for vibration analysis

In the interest of utilized more stable automobile components at high speed for reduction the vibration of mechanical system, dynamic characteristics analysis plays a vital role in complex mechanical parts. This paper introduces a clarified approach on statistical investigation and modal analysis methodology to study, predict and accurate crankshaft natural frequencies by using design of experiment (DOE). In this research, first, simulation had been done with MSC Nastran/ Patran to find out the natural frequencies in each mode shape of crankshaft as well as the verification with experiment was carried out. In order to less inaccuracy, numerous simplified crankshaft models were created by using these as input and DOE was established to acquire precise parameters of optimized crankshaft design as the second phase. This method can be further used for the optimizing the structural parameters and would provide some value basis to qualitative measure of parameters and determination of optimized structure. In Conclusion, modal verification accuracy between experimental and simulation has improved

Space network scheduling benchmark: A proof-of-concept process for technology transfer

This paper describes a detailed proof-of-concept activity to evaluate flexible scheduling technology as implemented in the Request Oriented Scheduling Engine (ROSE) and applied to Space Network (SN) scheduling. The criteria developed for an operational evaluation of a reusable scheduling system is addressed including a methodology to prove that the proposed system performs at least as well as the current system in function and performance. The improvement of the new technology must be demonstrated and evaluated against the cost of making changes. Finally, there is a need to show significant improvement in SN operational procedures. Successful completion of a proof-of-concept would eventually lead to an operational concept and implementation transition plan, which is outside the scope of this paper. However, a high-fidelity benchmark using actual SN scheduling requests has been designed to test the ROSE scheduling tool. The benchmark evaluation methodology, scheduling data, and preliminary results are described