Kindling the Spark of Black Male Genius through Education

This essay examines the nature of inopportunity associated with blackmaleness, synthesizes the narratives of the other contributors to this issue of the journal, and offers recommendations for how education can support Black males' academic, social, and cultural maturation. While African American males face daunting economic and educational challenges, James and Lewis argue that they can navigate through them to obtain academic and career success while still maintaining their identity as Black males

Coherence betwwen 19th century sperm whale distributions and satellite-derived pigments in the tropical Pacific

It has often been suggested that, given their large food requirements, sperm whale Physeter macrocephalus distributions should reflect the distribution of productive ocean environments, and it seems therefore that chlorophyll concentration might be a good indicator of sperm whale distribution. To examine the existence of such a relationship, and to determine over which sclaes it occurs, sperm whale density was correlated with phytoplankton pigment concentration over a range of spatial and temporal scales. Sperm whale distribution was detrmined using records of kills from 19th century Yankee whaling, and the distribution of pigment concentration from satellite colour observations averaged over 8yr interval. These measures were compared over scales of 220km square to 1780km square. The distribution of sperm whales in the temperature and tropical Pacific Ocean was associated with distributions of phytoplankton pigment over every spatial scale considered, and the coefficient of correlation increased with increasing spatial scale. However, a few exceptions to this scheme were found, implying that other factors would be of importance in some regions. This study confirmed the existence of space lag and a time lag between a peak in chlorophyll concentration and a peak in sperm whale density. It also demonstrated that over large spatial scales, and when the data are averaged over large temporal scales, chlorophyll concentration is a good indicator of sperm whale distribution and that over these scales ocean colour recorded from space could help predict areas of high or low sperm whale density

Thrombotic and Thromboembolic Complications in Patients with Adult Congenital Heart Disease

Improved medical and surgical interventions have increased the longevity of patients with congenital heart defects and most such patients live into adulthood. Thrombotic and thromboembolic complications constitute a major cause of mortality and morbidity in patients with adult congenital heart disease (ACHD). Such events include acute coronary syndromes, ischemic stroke (cardioembolic due to thrombus formation in the systemic ventricle, secondary to atrial arrhythmias, or due to paradoxical embolism), and venous thromboembolism. Some thrombotic phenomena are also specific to patients with ACHD, such as those related to Fontan circulation. We provide a succinct overview of thrombotic and thromboembolic complications in patients with ACHD, focusing on stroke and venous thromboembolic events

Why should we measure the optical backscattering coefficient?

In recent years commercial sensors for in situ determinations of optical backscattering coefficient, bb, have become available. The small size and low power requirements of these sensors permit deployment from small sensing platforms such as autonomous underwater vehicles, in addition to standard profiling packages. Given their rapid sampling time (sub second) they can collect data with high temporal and spatial resolution (sub meter). While these are attractive features of any sensor they do not answer the question: why should oceanographers measure bb? The short answer is that bb carries useful information about seawater constituents that scatter light. The potential to derive information about the abundance and the types of suspended marine particles, which play different roles in ocean ecosystems and biogeochemical cycling, is particularly attractive. To first order, the bb coefficient is a proxy for particle abundance but it also depends significantly on particle size distribution and particle composition, for example, on relative proportions of small and larger particles or on whether the particles are organic or inorganic. Most importantly, however, the spectral reflectance of the ocean (known as ocean color) is, to first order, proportional to bb. The measurements of ocean color from remote optical sensors on satellites provide a unique capability to monitor surface ocean properties (e.g., chlorophyll concentration and biological primary productivity) over extended spatial and temporal scales. Measurements and fundamental understanding of bb are required for understanding and successful applications of remotely sensed ocean color

A Configurable Matchmaking Framework for Electronic Marketplaces

E-marketplaces constitute a major enabler of B2B and B2C e-commerce activities. This paper proposes a framework for one of the central activities of e-marketplaces: matchmaking of trading intentions lodged by market participants. The framework identifies a core set of concepts and functions that are common to all types of marketplaces and can serve as the basis for describing the distinct styles of matchmaking employed within various market mechanisms. A prototype implementation of the framework based on Web services technology is presented, illustrating its ability to be dynamically configured to meet specific market needs and its potential to serve as a foundation for more fully fledged e-marketplace frameworks

Wave-induced light field fluctuations in measured irradiance depth profiles: A wavelet analysis

Rapid variations in the intensities of light are commonly observed in profiles of downwelling plane irradiance in the ocean. These fluctuations are often treated as noise and filtered out. Here an effort is made to extract the pertinent statistics to quantify the light field fluctuations from vertical profiles of irradiance measured under clear skies. The irradiance data are collected in oceanic and coastal waters using a traditional free-fall downwelling plane irradiance sensor. The irradiance profiles are transformed into time-frequency domain with a wavelet technique. Two signatures including the dominant frequency (<3.5 Hz) and the coefficient of variation of irradiance fluctuations along the water column are identified from the variance spectrum. Both the dominant frequency and the amplitude decrease as the inverse square root of depth, consistent with simple models of wave focusing and data from other studies. Mechanisms contributing to the observed variations and the observational uncertainties are discussed

Optical tools for ocean monitoring and research

© 2009 The Authors. This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Ocean Science 5 (2009): 661-684, doi: 10.5194/os-5-661-2009Requirements for understanding the relationships between ocean color and suspended and dissolved materials within the water column, and a rapidly emerging photonics and materials technology base for performing optical based analytical techniques have generated a diverse offering of commercial sensors and research prototypes that perform optical measurements in water. Through inversion, these tools are now being used to determine a diverse set of related biogeochemical and physical parameters. Techniques engaged include measurement of the solar radiance distribution, absorption, scattering, stimulated fluorescence, flow cytometry, and various spectroscopy methods. Selective membranes and other techniques for material isolation further enhance specificity, leading to sensors for measurement of dissolved oxygen, methane, carbon dioxide, common nutrients and a variety of other parameters. Scientists are using these measurements to infer information related to an increasing set of parameters and wide range of applications over relevant scales in space and time

Photosynthetic Characteristics and Estimated Growth Rates Indicate Grazing Is the Proximate Control of Primary Production in the Equatorial Pacific

Macronutrients persist in the surface layer of the equatorial Pacific Ocean because the production of phytoplankton is limited; the nature of this limitation has yet to be resolved. Measurements of photosynthesis as a function of irradiance (P-I) provide information on the control of primary productivity, a question of great biogeochemical importance. Accordingly, P-I was measured in the equatorial Pacific along 150°W, during February-March 1988. Diel variability of P-I showed a pattern consistent with nocturnal vertical mixing in the upper 20 m followed by diurnal stratification, causing photoinhibition near the surface at midday. Otherwise, the distribution of photosynthetic parameters with depth and the stability of P-I during simulated in situ incubations over 2 days demonstrated that photoadaptation was nearly complete at the time of sampling: photoadaptation had not been effectively countered by upwelling or vertical mixing. Measurements of P-I and chlorophyll during manipulations of trace elements showed that simple precautions to minimize contamination were sufficient to obtain valid rate measurements and that the specific growth rates of phytoplankton were fairly high in situ, a minimum of 0.6 d⁻¹. Diel variability of beam attenuation also indicated high specific growth rates of phytoplankton and a strong coupling of production with grazing. It appears that grazing is the proximate control on the standing crop of phytoplankton. Nonetheless, the supply of a trace nutrient such as iron might ultimately regulate productivity by influencing species composition and food-web structure

Reflecting Back to Forge the Path Forward

The JUME editorial team provides an update of the journal\u27s health and progress during the 2021 calendar year and discusses coming changes and opportunities for growth

The End or Beginning? Either Way, the Credits Are Not Rolling Yet!

(First paragraph) Thank you to all our reviewers, editorial board members, authors, and those who chose the Journal of Urban Mathematics Education (JUME) as their outlet of choice this past year. JUME has had many recent successes, and we in the editorial team plan to release the salient performance data for the journal. For JUME to advance its mission, we believe that accountability and transparency are essential. To this end, our readers will from now on receive an annual progress report about JUME in our first issue of each year