Antigen-driven CD4+ T cell and HIV-1 dynamics: Residual viral replication under highly active antiretroviral therapy

Antigen-induced stimulation of the immune system can generate heterogeneity in CD4+ T cell division rates capable of explaining the temporal patterns seen in the decay of HIV-1 plasma RNA levels during highly active antiretroviral therapy. Posttreatment increases in peripheral CD4+ T cell counts are consistent with a mathematical model in which host cell redistribution between lymph nodes and peripheral blood is a function of viral burden. Model fits to patient data suggest that, although therapy reduces HIV replication below replacement levels, substantial residual replication continues. This residual replication has important consequences for long-term therapy and the evolution of drug resistance and represents a challenge for future treatment strategies.

In vivo telomere dynamics of human hematopoietic stem cells

Aging in vivo and cell division in vitro are associated with telomere shortening. Several lines of evidence suggest that telomere length may be a good predictor of the long term replicative capacity of cells. To investigate the natural fate of chromosome telomeres of hematopoietic stem cells in vivo, we measured the telomere length of peripheral blood granulocytes from 11 fully engrafted bone marrow transplant recipients and from their respective donors. In 10 of 11 donor–recipient pairs, the telomere length was significantly reduced in the recipient and the extent of reduction correlated inversely with the number of nucleated cells infused. These data provide internally controlled in vivo evidence that, concomitantly with their proliferation, hematopoietic stem cells lose telomere length; it is possible that, as a result, their proliferative potential is reduced. These findings must be taken into account when developing new protocols in which few stem cells are used for bone marrow transplantation or for gene therapy.

In vivo estimates of division and death rates of human T lymphocytes.

We present data on the decay, after radiotherapy, of naive and memory human T lymphocytes with stable chromosome damage. These data are analyzed in conjunction with existing data on the decay of naive and memory T lymphocytes with unstable chromosome damage and older data on unsorted lymphocytes. The analyses yield in vivo estimates for some life-history parameters of human T lymphocytes. Best estimates of proliferation rates have naive lymphocytes dividing once every 3.5 years and memory lymphocytes dividing once every 22 weeks. It appears that memory lymphocytes can revert to the naive phenotype, but only, on average, after 3.5 years in the memory class. The lymphocytes with stable chromosome damage decay very slowly, yielding surprisingly low estimates of their death rate. The estimated parameters are used in a simple mathematical model of the population dynamics of undamaged naive and memory lymphocytes. We use this model to illustrate that it is possible for the unprimed subset of a constantly stimulated clone to stay small, even when there is a large population of specific primed cells reverting to the unprimed state.

Coherent electron dynamics in a two-dimensional random system with mobility edges

We study numerically the dynamics of a one-electron wavepacket in a two-dimensional random lattice with long-range correlated diagonal disorder in the presence of a uniform electric field. The time-dependent Schrodinger equation is used for this purpose. We find that the wavepacket displays Bloch-like oscillations associated with the appearance of a phase of delocalized states in the strong correlation regime. The amplitude of oscillations directly reflects the bandwidth of the phase and allows us to measure it. The oscillations reveal two main frequencies whose values are determined by the structure of the underlying potential in the vicinity of the wavepacket maximum.

Three Dichotomies in Lawyers’ Ethics (With Particular Attention to the Corporation as Client)

Three usually unexpressed, and too often unnoticed, conceptual dichotomies underlie our perception and understanding of lawyers’ ethics. First, the existence of a special body of professional ethics and professional regulation presupposes some special need or risk. Criminal and civil law are apparently insufficient. Ordinary day-to-day morality and ordinary ethics, likewise, are not considered to be enough. What is the risk entailed by the notion of a profession that is special; who needs protection, and from what? Two quite different possible answers to this question provide the first of the three dichotomies examined in this article: one can understand the risk as primarily to a vulnerable client from a powerful professional; or, to the contrary, from a powerful client-lawyer combination toward vulnerable others. Second, what is the foundational orientation of lawyers? Are lawyers serving primarily their particular clients, and those clients’ preferences, choices and autonomy? Or is the primary allegiance of lawyers to some community or collective goal or interest distinct from the particular goals or interests of the client? The third dichotomy concerns not the substance of the risk, or the primary orientation, but the appropriate means of responding to that risk or that fundamental obligation. Should professional ethics be implemented primarily through rules? Or, should we rely on character and the discretion of lawyers to make a thought out, all things considered, decision? Each of these three presents a fundamental difference in how we perceive and address issues of lawyers’ ethics. Each affects our understanding and analysis on multiple levels, from (1) determining the appropriate or requisite conduct in a particular situation, to (2) framing a specific rule or approach for a particular category of situations, to (3) more general or abstract theory or policy. A person’s inclinations in regard to the dichotomies affects the conclusions that person will reach on each of those levels of analysis, yet those inclinations and assumptions are frequently unexamined and unarticulated. One’s position on each of the dichotomies tends to structure the approach and outcome without the issues and choice having been explicitly addressed or possibly even noticed. This article is an effort to ameliorate that problem. Part I addresses the question of what is the risk in the work of lawyers, or the function of lawyers, for which professional ethics is the answer. The concluding section focuses on the particular problem of the corporation as client. Part II then asks the related and possibly consequent question of what is the foundational orientation or allegiance of the lawyer? Is it to the individual client? Or is it to some larger community interest? Again, the concluding section focuses on the corporation. Part III turns to the means or method for addressing the obligations and possible problems of the professional ethics of lawyers. Should lawyers’ ethics guide and confine the conduct of lawyers primarily through rules? Or should it function primarily through reliance on the knowledge, judgment and character of lawyers? If the latter were the guide, ethical decisions would be made on a situation by situation basis under the discretion of each lawyer. Toward the end of each discussion possibilities for bridging the dichotomy are considered (and with such bridges each dichotomy may come to look more like a spectrum or continuum.). At several points after its introduction in Parts I and II, the special problem of the corporation as client is revisited and possible solutions suggested. Illustrating the usefulness of keeping the dichotomies in view, Part IV applies them to several exemplary situations of ethical difficulty in actual lawyer practice. For readers finding it difficult to envision the consequences of these distinctions, turning ahead to Part IV may be useful in making the discussion more concrete. Some commonalities across the dichotomies and connections among them are then developed in the concluding section, Part V.

Three Dichotomies in Lawyers’ Ethics (With Particular Attention to the Corporation as Client)

Three usually unexpressed, and too often unnoticed, conceptual dichotomies underlie our perception and understanding of lawyers’ ethics. First, the existence of a special body of professional ethics and professional regulation presupposes some special need or risk. Criminal and civil law are apparently insufficient. Ordinary day-to-day morality and ordinary ethics, likewise, are not considered to be enough. What is the risk entailed by the notion of a profession that is special; who needs protection, and from what? Two quite different possible answers to this question provide the first of the three dichotomies examined in this article: one can understand the risk as primarily to a vulnerable client from a powerful professional; or, to the contrary, from a powerful client-lawyer combination toward vulnerable others. Second, what is the foundational orientation of lawyers? Are lawyers serving primarily their particular clients, and those clients’ preferences, choices and autonomy? Or is the primary allegiance of lawyers to some community or collective goal or interest distinct from the particular goals or interests of the client? The third dichotomy concerns not the substance of therisk, or the primary orientation, but the appropriate means of responding to that risk or that fundamental obligation. Should professional ethics be implemented primarily through rules? Or, should we rely on character and the discretion of lawyers to make a thought out, all things considered, decision? Each of these three presents a fundamental difference in how we perceive and address issues of lawyers’ ethics. Each affects our understanding and analysis on multiple levels, from (1) determining the appropriate or requisite conduct in aparticular situation, to (2) framing a specific rule or approach for a particular category of situations, to (3) more general or abstract theory or policy. A person’s inclinations in regard to the dichotomies affects the conclusions that person will reach on each of those levels of analysis, yet those inclinations and assumptions are frequently unexamined and unarticulated. One’s position on each of the dichotomies tends to structure the approach and outcome without the issues and choice having been explicitly addressed or possibly even noticed. This article is an effort to ameliorate that problem. Part I addresses the question of what is the risk in the work of lawyers, or the function of lawyers, for which professional ethics is the answer. The concluding section focuses on the particular problem of the corporation as client. Part II then asks the related and possibly consequent question of what is the foundational orientation or allegiance of the lawyer? Is it to the individual client? Or is it to some larger community interest? Again, the concluding section focuses on thecorporation. Part III turns to the means or method for addressing the obligations and possible problems of the professional ethics of lawyers. Should lawyers’ ethics guide and confine the conduct of lawyers primarily through rules? Or should it function primarily through reliance on the knowledge, judgment and character of lawyers? If the latter were the guide, ethical decisions would be made on a situation by situation basis under the discretion of each lawyer. Toward the end of each discussion possibilities for bridging the dichotomy are considered (and with such bridges each dichotomy may come to look more like a spectrum or continuum.). At several points after its introduction in Parts I and II, the special problem of the corporation as client is revisited and possible solutions suggested. Illustrating the usefulness of keeping the dichotomies in view, Part IV applies them to several exemplary situations of ethical difficulty in actual lawyer practice. For readers finding it difficult to envision the consequences of these distinctions, turning ahead to Part IV may be useful in making the discussion more concrete. Some commonalities across the dichotomies and connections among them are then developed in the concluding section, Part V.

Use of an Inverse Method for Time Series to Estimate the Dynamics of and Management Strategies for the Box Jellyfish Carybdea marsupialis

Frequently, population ecology of marine organisms uses a descriptive approach in which their sizes and densities are plotted over time. This approach has limited usefulness for design strategies in management or modelling different scenarios. Population projection matrix models are among the most widely used tools in ecology. Unfortunately, for the majority of pelagic marine organisms, it is difficult to mark individuals and follow them over time to determine their vital rates and built a population projection matrix model. Nevertheless, it is possible to get time-series data to calculate size structure and densities of each size, in order to determine the matrix parameters. This approach is known as a “demographic inverse problem” and it is based on quadratic programming methods, but it has rarely been used on aquatic organisms. We used unpublished field data of a population of cubomedusae Carybdea marsupialis to construct a population projection matrix model and compare two different management strategies to lower population to values before year 2008 when there was no significant interaction with bathers. Those strategies were by direct removal of medusae and by reducing prey. Our results showed that removal of jellyfish from all size classes was more effective than removing only juveniles or adults. When reducing prey, the highest efficiency to lower the C. marsupialis population occurred when prey depletion affected prey of all medusae sizes. Our model fit well with the field data and may serve to design an efficient management strategy or build hypothetical scenarios such as removal of individuals or reducing prey. TThis This sdfsdshis method is applicable to other marine or terrestrial species, for which density and population structure over time are available.

Petition of Sever and Welsteed to the General Court (manuscript copy), [1723 June-August]

Two folio-sized leaves containing a two-page handwritten copy of the June 21, 1723 petition of Sever and Welsteed requesting the question of non-resident Fellows in the Corporation be readdressed by the General Court, and a one-page handwritten copy of the answer to the petition passed by the General Court on August 7, 1723. The text of the petition begins "Sheweth that we have formerly represented to the Overseers of the College the Difficulty we were under in the business of it by reason of our not being vested with the power of its Charter..." The petition is incorrectly dated as "June 24th 1722" instead of 1723.

Memorial of the President and Fellows of Harvard College to the General Court for the enlargement of their power to hold real estate. Copy, [1797 July 15]

Four folio-sized leaves containing a handwritten copy of a petition to the Massachusetts General Court from the Harvard Corporation requesting the College's amount of tax exempt real estate be enlarged.

Vote of the Corporation, 1799 June 10

Two octavo-sized leaves containing a handwritten copy of the vote of the Harvard Corporation during the June 10, 1799 meeting authorizing Judge John Lowell and Judge Oliver Wendell to be a committee to attend to business with the state legislature related to the pending bill before the General Court regarding the College's real estate tax exemptions. The vote also authorized Professor Pearson to work with the Committee as needed. The document is addressed to Professor Pearson and signed by President Willard.

Short nomenclator or vocabular in English and Hebrew: composed alphabetically for the use and benefit of my pupils in particular and for the advantage of those who are desirous to obtain the knowledge of the Hebrew tongue in general, which may be that great help to understand not only ye sacred oracles in their original, but even any Jewish author (so far as concern owns) as also it may give great insight in ye tongue to those, as to compose it, a work altogether new, [ca. 1735]

Headed on the first page with the words "Nomenclatura hebraica," this handwritten volume is a vocabulary with the Hebrew word in the left column, and the English translation on the right. While the book is arranged in sections by letter, individual entries do not appear in strict alphabetical order. The small vocabulary varies greatly and includes entries like enigma, excommunication, and martyr, as well as cucumber and maggot. There are translations of the astrological signs at the end of the volume. Poem written at the bottom of the last page in different hand: "Women when good the best of saints/ that bright seraphick lovely/ she, who nothing of an angel/ wants but truth & immortality./ Verse 2: Who silken limbs & charming/ face. Keeps nature warm."

Polymer Fluid Dynamics: Continuum and Molecular Appoaches

To solve problems in polymer fluid dynamics, one needs the equation of continuity, motion, and energy. The last two equations contain the stress tensor and the heat-flux vector for the material. There are two ways to formulate the stress tensor: (1) one can write a continuum expression for the stress tensor in terms of kinematic tensors, or (2) one can select a molecular model that represents the polymer molecule, and then develop an expression for the stress tensor from kinetic theory. The advantage of the kinetic theory approach is that one gets information about the relation between the molecular structure of the polymers and the rheological properties. In this review, we restrict the discussion primarily to the simplest stress tensor expressions or “constitutive equations” containing from two to four adjustable parameters, although we do indicate how these formulations may be extended to give more complicated expressions. We also explore how these simplest expressions are recovered as special cases of a more general framework, the Oldroyd 8-constant model. The virtue of studying the simplest models is that we can discover some general notions as to which types of empiricisms or which types of molecular models seem to be worth investigating further. We also explore equivalences between continuum and molecular approaches. We restrict the discussion to several types of simple flows, such as shearing flows and extensional flows. These are the flows that are of greatest importance in industrial operations. Furthermore, if these simple flows cannot be well described by continuum or molecular models, then it is not necessary to lavish time and energy to apply them to more complex flow problems.

Community dynamics of stabilized dune xerophytic shrubs

Tese de doutoramento, Biologia (Ecologia), Universidade de Lisboa, Faculdade de Ciências, 2016

Legal Services Corporation : grantee attorneys' handling of migrant farmworker disputes with growers.

At head of title: Report to Congressional requesters.

Refugees and U.S. asylum seekers from Central America : statement of Nancy R. Kingsbury, Director, Foreign Economic Assistance Issues, National Security and International Affairs Division; before the Subcommittee on Immigration, Refugees, and International Law, Committee on the Judiciary, House of Representatives.

"For release ... March 9, 1989."