University of Massachusetts Boston

About: University of Massachusetts Boston is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Health care. The organization has 6541 authors who have published 12918 publications receiving 411731 citations. The organization is also known as: UMass Boston.

The Role of Language Comprehension in Mathematics and Problem Solving

Abstract: Modular containers containing soap, shampoo, or other bath liquids are arranged to be secured to the wall adjacent a bathtub or shower in side-by-side relationship by means of pressure responsive adhesive. Each of the containers includes interlocking structures on left and right side walls so that one or more of the containers can be interlocked together for positioning on the bathroom wall so that one or more different liquids are readily available for convenient use.

Systematic study of Ge1−xSnx absorption coefficient and refractive index for the device applications of Si-based optoelectronics

Abstract: The absorption coefficient and refractive index of Ge1−xSnx alloys (x from 0% to 10%) were characterized for the wavelength range from 1500 to 2500 nm via spectroscopic ellipsometry at room temperature. By applying physical models to fit the obtained data, two empirical formulae with extracted constants and coefficients were developed: (1) Absorption coefficient. The absorption regarding Urbach tail, indirect and direct bandgap transitions were comprehensively taken into account; (2) refractive index. The Sellmeier coefficients associated with dispersion relationship were extracted. In these formulae, the Sn composition and strain percentage were the input parameters, by inputting which the spectral absorption coefficient and spectral refractive index can be obtained. Since the absorption coefficient is key information to determine the performance of the photodetectors including operation wavelength range, responsivity, and specific detectivity, and the refractive index is very useful for the design of the anti-reflection coating for photodetectors and the layer structure for waveguides, the developed formulae could simplify the optoelectronic device design process due to their parameter-based expressions.

Paleontological baselines for evaluating extinction risk in the modern oceans

Abstract: Marine taxa are threatened by anthropogenic impacts, but knowledge of their extinction vulnerabilities is limited. The fossil record provides rich information on past extinctions that can help predict biotic responses. We show that over 23 million years, taxonomic membership and geographic range size consistently explain a large proportion of extinction risk variation in six major taxonomic groups. We assess intrinsic risk—extinction risk predicted by paleontologically calibrated models—for modern genera in these groups. Mapping the geographic distribution of these genera identifies coastal biogeographic provinces where fauna with high intrinsic risk are strongly affected by human activity or climate change. Such regions are disproportionately in the tropics, raising the possibility that these ecosystems may be particularly vulnerable to future extinctions. Intrinsic risk provides a prehuman baseline for considering current threats to marine biodiversity.

What is the origin of the common bean

Abstract: Systematists concerned with the origin of the common bean have disagreed or have been inconsistent in what name should be applied to the closest wild relatives of the domesticated Phaseolus vulgaris L. Phaseolus aborigineus Burk. (Berglund-Briicher and Briicher, 1976); P. aborigineus var. hondurensis Burk., P. vulgaris forma aborigineus Burk. (Burkart and Briicher, 1953); P. vulgaris ssp. aborigineus Burk. (Kloz et al., 1966); P. vulgaris L. (Gentry, 1969) are names which have been applied. With the present inadequate state of our knowledge concerning the biological relationships between the North and South American wild beans and between these wild types and the cultivars, P. vulgaris L. is the least ambiguous name for the wild species, escapes, cultivars and land races. The wild-growing South American populations may be distinguished informally by using "aborigineus" in conjunction with them. The wild types grow in isolated stands in a long and disjunct range from west central Mexico through Central America, along the eastern slopes of the Andes to northwestern Argentina (Gentry, 1969; Berglund-Briicher and Briicher, 1976) (Fig. 1). Miranda Colin (1967) and Gentry (1969) both suggested that at least one group of Phaseolus vulgaris domesticates evolved in the Mexico-Guatemala region, Mesoamerica. Berglund-Briicher and Briicher (1976) presented evidence for the domestication of P. vulgaris in South America. Neither group of authors explicitly ruled out the possibility of independent domestication in Mesoamerica and Andean America. A keen interest in the systematic and archaeological evidence bearing on single versus multiple regions of common bean domestication has been expressed by several writers on the origins of agriculture, among them DeCandolle in 1886 (1964), Mangelsdorf et al. (1964) and Heiser (1973). This paper presents further evidence to indicate that there remain substantial questions regarding the geographic origin of the common bean. The question of "origin" relevant to common bean domestication is examined with respect to how certain specific characters developed to distinguish domesticates from wild ancestors. Two of the traits that are characteristic of the common bean are extensive regional diversity and relatively large seed size. Extensive regional diversity is manifested by the presence of a large number of common bean land races, typically the vining rather than the dwarf types, grown in a region and recognizable by differences in seed color and pattern and in morphology. Large seed size as compared with Old World pulses was attributed to direct human selection by Carl 0. Sauer (1969) in lectures delivered in 1952. He viewed the distinctive New World system of planting single seeds contrasted with Old World broadcast sowing as permitting human selection for large seeds. Experimental and archaeological evidence are presented here to