Bostonia. Volume 12

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Nitrene transfer reactions by late transition metal complexes

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2007.Vita.Includes bibliographical references.This thesis presents nitrene transfer reactions that are catalyzed or mediated by late transition metal complexes. Sterically large, fluorinated supporting ligands are used to minimize potential side reactions. A new 1,10-phenanthroline ligand has been synthesized with 2,4,6-(CF3)3C6H2- groups in the 2- and 9-positions (1). A cationic copper(l) complex of 1 catalyzes nitrene transfer from N-(p-toluenesulfonylimino)phenyliodinane (PhlNTs) to the C-H bonds of 1,3-dimethoxybenzene in 63% yield. Altering the stoichiometry results in the formation of a different major product, N,N-bis(2',4'-dimethoxyphenyl)-p-toluenesulfonamide, in 33% yield. Treatment of a cationic copper(l) complex of 1 with p-nitrobenzenesulfonyl azide (NsN3) results in the formation of a rare mononuclear sulfonamido complex of copper(ll), 2. This complex is presumably formed via decomposition of a reactive sulfonimido complex of copper(lll). Although not a proficient nitrene transfer reagent to benzene, complex 2 is a precatalyst for nitrene transfer from NsN3 to benzene. Deprotonation of a palladium(ll) sulfonamido complex of 1 results in the formation of the first mononuclear sulfonimido complex of palladium,(cont.) 3. The sulfonimido ligand is bound in a K2-N,O chelate. This complex is a proficient nitrene transfer reagent to carbon monoxide, phosphines, and ethyl vinyl ether. A rhodium(lll) hydride chloride complex containing two N-heterocyclic carbene ligands, one of which is cyclometallated, is a convenient synthetic equivalent of a rhodium(l) chloride complex. Treatment of the rhodium(Ill) hydride with acetonitrile results in reductive elimination to form a rhodium(l) chloride complex. The chloride is readily abstracted by sodium azide to form a cationic rhodium(l) complex coordinated by two molecules of acetonitrile and containing an unbound azide. Upon exposure to UV light, this molecule undergoes cyclometallation to form a cationic rhodium(lll) hydride complex. The rhodium(lll) hydride chloride complex can be treated with oxygen to form a rhodium(lll) peroxide complex. The neutral peroxide complex has poor reactivity with trimethylphosphite and t-stilbene. However, a cationic rhodium peroxide complex oxidizes trimethylphosphite and t-stilbene at elevated temperatures.by Charles W. Hamilton.Ph.D

Investigating the effects of planting date and Aphis gossypii management on reducing the final incidence of cotton leafroll dwarf virus

This is the first study to research management strategies for cotton leafroll dwarf virus (CLRDV) in the southeastern U.S. The efficacy of aphid vector management to reduce final CLRDV incidence was investigated concurrent with efforts to monitor aphid population dynamics and timing of CLRDV spread. Adjusting the planting date and insecticide applications did not reduce the final incidence of CLRDV, which was confirmed in 60–100% of plants per plot using RT-PCR. Aphid population density was reduced, but not eliminated with foliar insecticide applications. Aphis gossypii was the only species observed on cotton and was the dominant species collected in pan traps. Three distinct periods of virus spread were detected with sentinel plants including early, mid-and late-season. Most virus spread occurred during large aphid dispersal events

Evolution of non-kin cooperation:social assortment by cooperative phenotype in guppies

© 2019 The Authors. Cooperation among non-kin constitutes a conundrum for evolutionary biology. Theory suggests that non-kin cooperation can evolve if individuals differ consistently in their cooperative phenotypes and assort socially by these, such that cooperative individuals interact predominantly with one another. However, our knowledge of the role of cooperative phenotypes in the social structuring of real-world animal populations is minimal. In this study, we investigated cooperative phenotypes and their link to social structure in wild Trinidadian guppies (Poecilia reticulata). We first investigated whether wild guppies are repeatable in their individual levels of cooperativeness (i.e. have cooperative phenotypes) and found evidence for this in seven out of eight populations, a result which was mostly driven by females. We then examined the social network structure of one of these populations where the expected fitness impact of cooperative contexts is relatively high, and found assortment by cooperativeness, but not by genetic relatedness. By contrast, and in accordance with our expectations, we did not find assortment by cooperativeness in a population where the expected fitness impact of cooperative contexts is lower. Our results provide empirical support for current theory and suggest that assortment by cooperativeness is important for the evolution and persistence of non-kin cooperation in real-world populations

Long-term improvements following a residential combined physical and psychological programme for chronic low back pain

Objectives Evaluate the outcomes and explore experiences of patients undergoing a residential combined physical and psychological programme (CPPP) for chronic low back pain. Design A longitudinal observational cohort design, with a parallel qualitative design using semistructured interviews. Setting Residential, multimodal rehabilitation. Participants 136 adults (62 male/74 female) referred to the CPPP, 100 (44 male/56 female) of whom completed the programme, during the term of the study. Ten (2 male/8 female) participated in the qualitative evaluation. Intervention A 3-week residential CPPP. Outcome measures Primary outcome measures were the STarT Back screening tool score; pain intensity-11-point Numerical Rating Scale; function-Oswestry Disability Index (ODI); health status/quality of life-EQ-5D-5L EuroQol five-Dimension-five level; anxiety-Generalised Anxiety Disorder-7; depression-Patient Health Questionnaire-9. Secondary outcome measures were the Global Subjective Outcome Scale; National Health Service Friends and Family Test;. Results At discharge, 6 and 12 months follow ups, there were improvements from baseline that were greater than minimum clinically important differences in each of the outcomes (with the sole exception of ODI at discharge). At 12 months, the majority of people considered themselves a lot better (57%) and were extremely likely (86%) to recommend the programme to a friend. The qualitative data showed praise for the residential nature of the intervention and the opportunities for interaction with peers and peer support. There were testimonies of improvements in understanding of pain and how to manage it better. Some participants said they had reduced, or stopped, medication they had been taking to manage their pain. Conclusions Participants improved, and maintained long term, beyond minimum clinically important differences on a wide range of outcomes. Participants reported an enhanced ability to self-manage their back pain and support for the residential setting

Loss of Biological Diversity: A Global Crisis Requiring International Solutions: A Report to the National Science Board

Executive Summary Biological diversity refers to the variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequency. For biological diversity, these items are organized at many levels, ranging from complete ecosystems to the chemical structures that are the molecular basis of heredity. Thus, the term encompasses different ecosystems, species, genes, and their relative abundance (OTA, 1987). There is an ongoing, unprecedented loss of the variety as well as absolute numbers of organisms-from the smallest microorganism to the largest and most spectacular of mammals. Loss of tropical moist forests, which contain over half the total species of organisms, has been well documented by scientists and is now widely reported in the media. Many other ecosystems are also threatened; as human populations and their support systems expand, natural ecosystems at all latitudes are altered or converted. At its meeting on October 15, 1987, the National Science Board concluded that the world\u27s decreasing biological diversity is a critical scientific issue requiring immediate attention. The National Science Board\u27s Committee on International Science was asked to study the scientific and international aspects of the decline of biological diversity and to recommend a course of action. This report describes what the National Science Foundation (NSF) can do to influence the U.S. science and education base, articulates where international scientific cooperation is needed, and suggests roles for other agencies and organizations (both national and international) which have scientific, educational, and management responsibilities. The current disappearance of biota has several causes: the destruction or degradation of entire ecosystems; the accelerating loss of individual species from communities or ecosystems as a result of human disturb;mce; and the loss of genetically distinct parts of populations due to human-induced selective pressures. Although not all parts of the planet are equally affected, the problem is global, and human activities are the primary cause. The loss of biological diversity is important because human existence depends on the biological resources of 1 the earth. Human prosperity is based very largely on the ability to utilize biological diversity: to take advantage of the properties of plants, animals, fungi, and microorganisms for food, clothing, medicine, and shelter. Scientific knowledge about the earth\u27s biological diversity has huge gaps. This lack of information hampers society\u27s ability either to estimate the magnitude of the problem or to prevent further losses. It is impossible to identify all the biological resources at risk, since there is no complete inventory of all the life forms on earth. Approximately 1.4 million species have been given scientific names, but estimates of actual numbers range from 5 million to 80 million species. Although knowledge of some taxa is extensive, the vast majority of groups are largely unknown. The current wave of extinction is destroying both known biotic resources and those still undiscovered. As is proving to be the case with most environmental problems, neither the loss of biological diversity nor its solution is the exclusive province of any one nation. International cooperation is necessary to develop both scientific knowledge and successful mitigation and management strategies. The root causes of the problem include sociological and economic processes which operate on an global scale; a thorough understanding will require investigation and elucidation of both biological and non-biological components. There are several reasons for increasing National Science Foundation (NSF) involvement in biodiversity studies: the economic and social importance of biodiversity (and the risk of opportunity lost due to accelerating extinction); the contributions such leadership can make toward to conservation of biological diversity; the important role of such studies in the international growth of science, especially in tropical countries; the potential impact of such studies on the future course of biology as a whole; and enhancing public awareness of the issues. NSF should assume a scientific leadership position with respect to agencies in the U.S. and throughout the world. By insisting on the central importance of biodiversity, the NSF could encourage collaborative support for the actions recommended below. 1. The Committee believes that the role of the NSF is clear-NSF should, as a matter of National Science Board Policy, provide leadership to undertake the inventory of the world\u27s biodiversity. 2. The scientific basis for conservation biology, restoration ecology, and environmental management must be strengthened. 3. Educational and public awareness programs related to biodiversity need increased support. 4. The economic and social aspects of the biodiversity crisis need additional study. 5. Enhance support for developing country scientists and institutions for biodiversity research and conservation

1969: Abilene Christian College Bible Lectures - Full Text

GOD’S ETERNAL PURPOSE Being the Abilene Christian College Annual Bible Lectures 1969 Published by ABILENE CHRISTIAN COLLEGE BOOK STORE ACC Station Abilene, Texas 7960

Kochen-Specker Vectors

We give a constructive and exhaustive definition of Kochen-Specker (KS) vectors in a Hilbert space of any dimension as well as of all the remaining vectors of the space. KS vectors are elements of any set of orthonormal states, i.e., vectors in n-dim Hilbert space, H^n, n>3 to which it is impossible to assign 1s and 0s in such a way that no two mutually orthogonal vectors from the set are both assigned 1 and that not all mutually orthogonal vectors are assigned 0. Our constructive definition of such KS vectors is based on algorithms that generate MMP diagrams corresponding to blocks of orthogonal vectors in R^n, on algorithms that single out those diagrams on which algebraic 0-1 states cannot be defined, and on algorithms that solve nonlinear equations describing the orthogonalities of the vectors by means of statistically polynomially complex interval analysis and self-teaching programs. The algorithms are limited neither by the number of dimensions nor by the number of vectors. To demonstrate the power of the algorithms, all 4-dim KS vector systems containing up to 24 vectors were generated and described, all 3-dim vector systems containing up to 30 vectors were scanned, and several general properties of KS vectors were found.Comment: 19 pages, 6 figures, title changed, introduction thoroughly rewritten, n-dim rotation of KS vectors defined, original Kochen-Specker 192 (117) vector system translated into MMP diagram notation with a new graphical representation, results on Tkadlec's dual diagrams added, several other new results added, journal version: to be published in J. Phys. A, 38 (2005). Web page: http://m3k.grad.hr/pavici