Three Reductions, Three Gains (3R3G) Technology in South Vietnam: Searching for Evidence of Economic Impact

The aim of the “Three Reductions, Three Gains” (3R3G) project is to reduce production costs, improve farmers’ health, and protect the environment in irrigated rice production in Vietnam through the reduced use of seeds, nitrogen fertilizer, and pesticides. It was developed by the International Rice Research Institute and introduced to farmers in South Vietnam by the Ministry of Agriculture and Rural Development in early 2000 through traditional extension work and mass media. Farm survey data provide evidence of adoption of 3R3G primarily in terms of lowering seed rates. The resultant changes in the farm production/cost structure and farmer profits are measured.information-intensive technology, technology transfer, farm-level impacts, Environmental Economics and Policy, Farm Management, Productivity Analysis,

What Makes Conversation Good? How Responsivity, Topics, and Insider Language Predict Feelings of Connection

We spend our lives having conversations, and some inevitably go better than others. What happens in conversation that makes people feel connected? To explore this question, I recorded pairs of strangers and friends having unstructured conversations. In Chapter 1, I show that people who feel connected tend to respond quickly, creating short gaps between turns. However, long gaps are not necessarily bad. Although long gaps signal moments of disconnection and awkwardness for strangers, they mark moments of heightened connection for friends by providing space for enjoyment and mutual reflection. In Chapter 2, I examine how people start their conversations. Specifically, how do people who have never met before initiate their first interaction? And how do these approaches differ from people who are already robustly connected? I find that strangers start their conversations more similarly to each other, compared to friends. In particular, strangers tend to start with topics that can easily launch into many different topics, increasing the likelihood of finding common ground. Friends do not need to rely on this strategy and can instead immediately start their conversations with topics idiosyncratic to their relationship. In Chapter 3, I highlight another fundamental difference in how friends and strangers communicate by exploring the use of insider language, or words carrying specific meaning between some people but not others. I find that friends use insider language more than strangers and when they do, they feel more connected. When people know each other well, communication can move from spoken words to shared thoughts. Together, these findings reveal that people feel closer when they can respond quickly in conversation and feel comfortable not speaking, and that being able to jump right into a conversation and communicate using shorthand are hallmarks of friendship

The pulsation spectrum of VX Hydrae

We present the results of a two-year, multisite observing campaign investigating the high-amplitude delta Scuti star VX Hydrae during the 2006 and 2007 observing seasons. The final data set consists of nearly 8500 V-band observations spanning HJD 2453763.6 to 2454212.7 (2006 January 28 to 2007 April 22). Separate analyses of the two individual seasons of data yield 25 confidently-detected frequencies common to both data sets, of which two are pulsation modes, and the remaining 23 are Fourier harmonics or beat frequencies of these two modes. The 2006 data set had five additional frequencies with amplitudes less than 1.5 mmag, and the 2007 data had one additional frequency. Analysis of the full 2006-2007 data set yields 22 of the 25 frequencies found in the individual seasons of data. There are no significant peaks in the spectrum other than these between 0 and 60 c/d. The frequencies of the two main pulsation modes derived from the 2006 and 2007 observing seasons individually do not differ at the level of 3-sigma, and thus we find no conclusive evidence for period change over the span of these observations. However, the amplitude of f(1) = 5.7898 c/d changed significantly between the two seasons, while the amplitude of f(0) = 4.4765 c/d remained constant; amplitudes of the Fourier harmonics and beat frequencies of f(1) also changed. Similar behavior was seen in the 1950s, and it is clear that VX Hydrae undergoes significant amplitude changes over time.Comment: 14 pages, 5 figures, published in Publications of the Astronomical Society of the Pacific, v.121, p.1076 (October 2009

Structural aspects of molecular recognition in the immune system. Part I: Acquired immunity (IUPAC Technical Report)

Humoral immunity allows the body to mount a defense against pathogens and foreign substances, and to respond with memory to subsequent exposures. The molecular participants may also recognize self-structures, leading to attack on the body and autoimmune disease. The main players in humoral immunity are antibody-producing B lymphocytes, and several classes of T lymphocytes. This review deals with the molecular details of recognition of antigens by soluble antibodies, and of substances presented to receptors on the surfaces of T cells (TCRs). The prototype antibody consists of a dimer of dimers, two heavy (H) chains and two light (L) chains, with antigen recognition capacity lying in variable "head” regions of an H-L pair. Most crystallographic studies are done with this substructure, called a Fab fragment, bound in a soluble antigen complex. Homologous to this arrangement, the prototype TCR consists of two chains (α and β) that complex not soluble antigen, but usually a short peptide or other small molecule presented by proteins of the major histocompatibility complex. In each case a general background on the historical development of understanding the molecular recognition interface is given, followed by a number of examples of crystal structures from the recent literature that have allowed us to refine our understanding of the complex recognition process. Variations on the prototypical structures are also considered. The spectrum of recognition strategies involves interplay of lock-and-key with flexibility, varying degrees of entropic and enthalpic contributions, surface shaping by entrapped water molecules, and combinations of stabilizing hydrogen bonding, electrostatic interactions, salt bridging, and van der Waals forces. Preeminent in the recent literature are details of antibody binding to influenza A and human immunodeficiency viral antigens. Both viral antigens and attempts to understand autoimmunity are prominent in the recent TCR literatur