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Marine renewable energy development aims to harness the vast resources of the coastal environment to meet growing energy demands. Among the variety of coastal energy sources, salinity gradient energy (SGE) technology captures the energy released from the controlled mixing of waters of different salinities found naturally in estuarine systems or in other combinations of anthropogenic sources of brine and fresh waters. Although SGE technology is in the pilot stage of development, there is currently no comprehensive published assessment of its environmental impacts. This assessment uses research from proxy facilities and pilot SGE projects to predict impacts of an SGE facility through construction, operation and decommission phases. Construction and decommission of an SGE facility is expected to disrupt habitat and organisms via noise, land modification, and release of pollutants, similar to other coastal facilities such as desalination plants or water intake cooling structures. During operation, however, impacts unique to SGE result from intake of both high- and low-salinity waters, which in natural sources will involve impingement, entrainment, and chemical treatment to reduce biofouling. In addition, SGE effluent is expected to be of lower salinity and higher volume than effluent from a desalination plant, thereby posing unique risks to discharge sites. This review highlights areas of concern and lack of knowledge, which can guide environmental impact assessment and monitoring priorities of site managers.

Evolutionary researchers have sometimes taken findings of low variation in the size or shape of a biological feature to indicate that it is functional and under strong evolutionary selection, and have assumed that high variation implies weak or absent selection and therefore lack of function. To test this assumption we compared the size variation (using a mean-adjusted measure of absolute variability) of the functional human female nipple (defined as the nipple-areola complex) with that of the non-functional human male nipple. We found that female nipples were significantly more variable than male nipples, even after controlling for body mass index, testing-room temperature, bust size in women, and chest size in men. Morphological variation in a feature should not be used by itself to infer whether or not the feature is functional or under selection.

Global estimates of electricity generation from coastal salinity gradient energy resources rely on the underlying assumption that these gradients are spatially and temporally stable. Refining these estimates requires a better understanding of coastal variations in water properties and their impact on power production. This study investigated power output in reverse electrodialysis (RED) cells by coupling seawater samples collected from three different sites along coastal North Carolina at five different sampling dates between 2016 and 2017 with wastewater effluent from a wastewater treatment facility as the dilute solution. We found that power density did not vary substantially across the sampling dates except for one notable drop in power for a sample collected during an approaching hurricane. For all sites, power output peaked during the summer season. Using our experimental results, we developed a semi-empirical predictive model of RED power output as a function of temperature and conductivity. The model was able to predict power density within approximately 20% of the experimental power densities for the seawater samples used in this study and others in the literature. Combining our modeling approach with temporal conductivity and temperature data may help identify promising sites for coastal salinity gradient energy installations.

Evolutionary theory makes further predictions about conflict. It predicts sex differences in the proclivity to attack and defend. It further suggests complementary biases in what we expect of the sexes. Finally, it suggests that the forms of human facial expressions of anger and happiness may have coevolved with the regularity of conflict as a means of signaling, bluffing, and defusing attack.

Four studies and a computer simulation tested the hypothesis that people who are overconfident in their self-assessments may be more successful in attracting mates. In Study 1, overconfident people were perceived as more confident in their dating profiles, and this perceived confidence predicted increased romantic desirability. Study 2 revealed that overconfident people also tend to be perceived as arrogant, which counteracts the positive effects of perceived confidence. However, Study 3 revealed that overconfidence might confer an advantage in intrasexual competition, as people were less likely to compete with overconfident individuals by virtue of their perceived confidence and arrogance. Study 4 showed that overconfident raters were also more likely to choose to compete for romantic partners. In Study 5, agent-based modeling incorporating the coefficients from these studies suggested that overconfidence facilitates mate acquisition in the presence of intrasexual competition.

Human mate choice is complicated, with various individual differences and contextual factors influencing preferences for numerous traits. However, focused studies on human mate choice often do not capture this multivariate complexity. Here, we consider multiple factors simultaneously to demonstrate the advantages of a multivariate approach to human mate preferences. Participants ( N =689) rated the attractiveness of opposite-sex online dating profiles that were independently manipulated on facial attractiveness, perceived facial masculinity/femininity, and intelligence. Participants were also randomly instructed to either consider short- or long-term relationships. Using fitness surfaces analyses, we assess the linear and nonlinear effects and interactions of the profiles' facial attractiveness, perceived facial masculinity/femininity, and perceived intelligence on participants' attractiveness ratings. Using hierarchical linear modeling, we were also able to consider the independent contribution of participants' individual differences on their revealed preferences for the manipulated traits. These individual differences included participants' age, socioeconomic status, education, disgust (moral, sexual, and pathogen), sociosexual orientation, personality variables, masculinity, and mate value. Together, our results illuminate various previously undetectable phenomena, including nonlinear preference functions and interactions with individual differences. More broadly, the study illustrates the value of considering both individual variation and population-level measures when addressing questions of sexual selection, and demonstrates the utility of multivariate approaches to complement focused studies.

We argue that mate rejection and ex-partner relationships are important, multifaceted topics that have been underresearched in social and evolutionary psychology. Mate rejection and relationship dissolution are ubiquitous and form integral parts of the human experience. Both also carry with them potential risks and benefits to our fitness and survival. Hence, we expect that mate rejection would have given rise to evolved behavioral and psychological adaptations. Herein, we outline some of the many unanswered questions in evolutionary psychology on these topics, at each step presenting novel hypotheses about how men and women should behave when rejecting a mate or potential mate or in response to rejection. We intend these hypotheses and suggestions for future research to be used as a basis for enriching our understanding of human mating from an evolutionary perspective.

It has been shown that a smaller ratio between the length of the second and fourth digit (2D:4D) is an indicator of the exposure to prenatal testosterone (T). This study measured the 2D:4D of men and assessed dominance as a personality trait to investigate indirectly if the exposure to prenatal T is related to a dominant personality later in life. Results showed that men had a more aggressive dominant personality when having a more masculine (lower) 2D:4D, while there was no relationship between sociable dominance and 2D:4D. Findings from this study indicate that it is important to distinguish different forms of dominance since other studies failed to find relationships between dominance and 2D:4D. Aggr. Behav. 38:208-212, 2012. © 2012 Wiley Periodicals, Inc. Language: en

Although parental influence over mate choice is important to human mating decisions, it is often overlooked within evolutionary psychology. Based on evolutionary theory, we predict that, while both parents likely influence a child’s mate choice, daughters will perceive having a low quality partner (i.e., traits indicating poor parental investment, a lack of creativity, and physical unattractiveness) would be more unacceptable to their mother when compared with the father. However, daughters will perceive having a partner with traits indicating low social status as more unacceptable to their father when compared with the mother. The results supported the hypotheses.

We compared, from 2004 through 2006, rates of soil–atmosphere CH4 exchange at permanently established sampling sites in a temperate forest exposed to ambient (control plots; ∼380 μL L−1) or elevated (ambient + 200 μL L−1) CO2 since August 1996. A total of 880 observations showed net atmospheric CH4 consumption (flux from the atmosphere to the soil) from all static chambers most of the time at rates varying from 0.02 mg m−2 day−1 to 4.5 mg m−2 day−1. However, we infrequently found net CH4 production (flux from the soil to the atmosphere) at lower rates, 0.01 mg m−2 day−1 to 0.08 mg m−2 day−1. For the entire study, the mean (±SEM) rate of net CH4 consumption in control plots was higher than the mean for CO2-enriched plots, 0.55 (0.03) versus 0.51 (0.03) mg m−2 day−1. Annual rates of 184, 196, and 197 mg m−2 for net CH4 consumption at control plots during the three calendar years of this study were 19, 10, and 8% higher than comparable values for CO2 enriched plots. Differences between treatments were significant in 2004 and 2005 and nearly significant in 2006. Volumetric soil water content was consistently higher at CO2-enriched sites and a mixed-effects model identified a significant soil moisture x CO2 interaction on net atmospheric CH4 consumption. Increased soil moisture at CO2-enriched sites likely increases diffusional resistance of surface soils and the frequency of anaerobic microsites supporting methanogenesis, resulting in reduced rates of net atmospheric CH4 consumption. Our study extends our observations of reduced net atmospheric CH4 consumption at CO2-enriched plots to nearly five continuous years, suggesting that this is likely a sustained negative feedback to increasing atmospheric CO2 at this site.

Dilution bioassays were conducted to evaluate the impact of nutrients on biomass (chlorophyll a), photosynthetic potential, and class composition of suspended algal assemblages in the middle Cape Fear River (USA). Ambient concentrations of dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) varied from 37.2 to 83.8 and from 1.0 to 7.1 μmol L–1. Experiments conducted at photosynthetic photon flux densities (PPFDs) similar to the mixed water column (< 1 to 5.3 E m–2d–1) showed no change in chlorophyll a, photosynthetic potential, or algal class composition at 15, 30, and 45% dilutions of DIN, SRP, or both. However, chlorophyll a and photosynthetic potential increased significantly in nutrient dilution bioassays conducted at PPFDs four-fold above ambient, while the abundance of diatoms and Chrysophytes increased under elevated PPFD and ambient or elevated nutrients. Overall, the data indicate that irradiance is more important than nutrients in determining the size and class composition of suspended algal assemblages. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Prevailing evolutionary approaches to human mating have largely ignored the fact that mating decisions are heavily influenced by parents and other kin. This is significant because parents and children often have conflicting mate preferences. We provide a brief review of how parents have influenced their children's mating behavior across cultures and throughout history. Then, by drawing on evolutionary reasoning, we offer a hypothesis for why parents and offspring may have conflicting interests with respect to mate preferences. Specifically, parents may have a relatively stronger preference for children's mates with characteristics suggesting high parental investment and cooperation with the ingroup, whereas children may have a relatively stronger preference for mates with characteristics signaling heritable fitness. We review past research consistent with this hypothesis, and we report new results from an empirical study consisting of 768 participants from a variety of cultures that provided clear support for the hypothesis.

Pelagic Sargassum macroalgae entrained in the Gulf Stream serves as habitat for commercially and recreationally important fish and protected sea turtles, among other organisms. It also plays an important role in the sourcing of carbon, nitrogen, and phosphorus to the otherwise deficient oligotrophic pelagic waters of the Atlantic Ocean.

Intrasexual competition between women is a critically important construct with real implications for women’s physical and psychological health. This chapter argues that female competition can cause women to fixate on their appearance and take unnecessary risks in an effort to improve it. Western society sets seemingly impossible criteria for female beauty that few women can naturally—and healthily—achieve. These standards and evolved partner preferences for physical attractiveness in women help to explain why women generally feel enormous pressure to be attractive and are compelled to compete intensely with one another in the realm of physical attractiveness. The authors suggest that intrasexual competition may lead some women to alter their physical appearance through unnecessary, expensive, and ultimately risky medical procedures in order to outdo female mating rivals and attain the best-quality mate. This is may be a dangerous strategy, equivalent to the overt risk-taking behaviors that exemplify male–male intrasexual competition.

A content analysis of the 4 extant undergraduate textbooks on family communication examined tables of contents, indexes, headings within the text, and illustrative examples, to discover the amount of coverage the authors devote to issues of gender and diversity. Friedman's two-way analyses of variance by ranks revealed significant differences between the books in the amount of coverage devoted to diversity issues; the books did not differ significantly in the amount of coverage devoted to gender issues. We observed that the books varied widely in the specific issues they addressed in their treatment of diversity and gender concerns, and based on the findings, offer specific recommendations for textbook adoption.

The publication of To Err Is Human has highlighted concern for patient safety. Attention to date has focused primarily on micro issues such as minimizing medication errors and adverse drug reactions, improving select aspects of care, and reducing diagnostic and treatment errors. However, attention is also required to a macro issue--an organization's culture and the level of leadership required to create a culture. This article discusses the concepts of culture and leadership and summarizes two paradigms that are useful in understanding the precursors of medical errors and developing interventions to prevent them: normal accident theory and high-reliability organization theory. It also delineates approaches to instilling a safety culture. Normal accident theory asserts that errors result from system failures. An important element of this perspective is the need for a system that collects, analyzes, and disseminates information from incidents and near misses as well as regular proactive checks on the system's vital signs. Four subcultures are necessary to support such an environment: a reporting culture, a just culture, a flexible culture, and a learning culture. High-reliability organization theory posits that accidents occur because individuals who operate and manage complex systems are themselves not sufficiently complex to sense and anticipate the problems generated by the system. Lessons learned from high-reliability organizations indicate that a safety culture is supported by migrated distributed decision making, management by exception or negotiation, and fostering a sense of the "big picture." Lessons from other industries are also shared in this article.

There has been much discussion of the appropriateness of various organizational strategies for today's healthcare industry. This article presents case studies of two healthcare organizations that have pursued very different configurations. PennCARE uses a virtually integrated, loose contract-based arrangement, while Henry Ford Health System employs a vertically integrated, tight ownership model. Despite these different approaches, their overall designs are strikingly similar. In essence both systems demonstrate a property called organizational design consistency; they simply approach it from different ends of the spectrum. This article presents the notion of organizational design consistency and defines it as the steady pursuit of a single preferred configuration strategy across key elements of organizational design. To illustrate the framework the case studies target four key elements of organizational design (governance structure, organizational culture, strategic planning processes, and decision-making procedures) and explain how consistency across these components adds value to both of these differently configured healthcare systems. There is room enough for diverse configurations of organizations in the current healthcare environment. Consistency does not mandate conformity; value can be derived from both tight and loose models. Furthermore, when fashioning organizational design consistency strategies, healthcare systems should carefully choose tightly or loosely modeled configurations to appropriately suit their aims, their markets, and the capabilities and resources available to them.

This paper revisits the 1994 taxonomy of health networks and systems in order to: a) assess how the original cluster categories of hospital-led health networks and systems have changed over time; a...

Throughout the 1990s health care providers were interested in developing organized delivery systems. However, industry observers have increasingly questioned the sense of these efforts. Using an established taxonomy of health networks and systems, we examined whether there was a nationwide trend away from the vertical and horizontal arrangements that serve as the backbone to organized delivery systems. Studying 1994-1998, we found that both health networks and systems became less centralized in their hospital services, physician arrangements, and insurance product development. We did not find a general pathway to disintegration but instead found considerable experimentation in organizational form.

This article illustrates how a new approach to classifying health networks and systems can be used to evaluate the readiness of health care organizations to accept risk. Examples are provided from the Harris-Methodist, Henry Ford, and SSM Health Care Systems. The classification system can also be used to assist executives and physician leaders in making decisions involving the centralization of services, the number of different services to offer, and decisions to enter into various strategic alliances. The classification system can be updated to help track the evolution of the U.S. health care system over time.

We examined the role of social dominance orientation (SDO) as a predictor of men’s reactions to romantic rejection and attitudes toward female sexuality. In Study 1 (n = 158), we found that men who scored higher in SDO were more likely to blame women for romantic rejection, and report having responded to women’s past rejection with persistence and manipulation (e.g., convincing her to “give him another chance”), as well as with aggression and threats of violence. In Study 2 (n = 398), we replicated these findings, and further found that men higher in SDO were more likely to endorse rape myths (e.g., believing that sometimes a woman’s barriers need to be “broken down” in order to attain sex), and to want to lower the legal age of sexual consent in women. Two mediators explained this relationship, hostile sexism and the belief that insubordinate women need to be disciplined. Practical and theoretical implications are discussed.

Avoiding disease and acquiring resources have been recurrent challenges throughout human evolution. These abilities are particularly relevant to mate preferences, as pathogens and resources can both be transferred between mates and to mutual offspring. Based on 689 participants’ attractiveness ratings of manipulated online dating profiles, we tested whether pathogen and resource concerns predicted revealed mate preferences for facial attractiveness, facial sexual dimorphism, and perceived intelligence and also whether these different trait preferences were intercorrelated. Supporting our predictions, pathogen concerns positively predicted men and women’s preferences for facial attractiveness and men’s preference for facial femininity, whereas women’s resource concerns negatively predicted their preference for facial masculinity. Unexpectedly, neither pathogen nor resource concerns predicted preference for greater perceived intelligence. Further, preference for perceived intelligence was negatively correlated with preference for facial attractiveness, which was positively correlated with preference for facial sexual dimorphism. These findings suggest that facial attributes are used in mate assessment as cues of health and likelihood of resource provisioning, whereas intelligence may primarily be used as a cue of other, distinct qualities.

To assess the ecological impact of extracting energy from the Gulf Stream, the University of North Carolina Coastal Studies Institute has deployed a mooring on the continental slope off Cape Hatteras at a depth of 230 m, equipped with an ADCP, a CTD, and a hydrophone. Analyzing data from the first deployment, we automatically detected marine mammal vocalizations. We found a strong correlation between the amount of vocalizations and the position of the Gulf Stream, with vocalizations increasing when the Gulf Stream was farther offshore. We then derived sound speed profiles for the region around the mooring using temperature and salinity profiles collected by WHOI Spray gliders. These sound speed profiles were fed into a propagation modeling tool. When the Gulf Stream was far offshore with respect to the mooring position, the model showed a set of rays that propagate down the slope in an acoustic channel along the bottom. When the Gulf Stream was nearly over the mooring, the range of angles that could propa...

This study investigated gender differences in parental monitoring and sensitivity toward parents and the extent to which these measures can influence children's mate preferences. In 2 samples (the United States and the Netherlands), females reported experiencing higher levels of parental monitoring and being more sensitive toward their parents' feelings regarding mate choice (e.g., being more upset if their parents did not approve of their partner) than males. Individuals displaying higher sensitivity toward parents rated parental investment and cooperation, and to a lesser extent genetic quality, as being more important in a potential mate than individuals lower in sensitivity toward parents. The level of parental monitoring did not significantly predict the importance of parental investment and cooperation or genetic quality in a potential mate.

Previous research reveals that children and parents are not in complete agreement over which traits are most important for the mate of the child. Children tend to prefer traits that suggest genetic quality, whereas parents prefer characteristics that suggest high parental investment and cooperation with the ingroup. Using a sample of parents, mothers (n = 234) and fathers (n =240) the hypothesis was supported; parents perceived characteristics indicating a lack of genetic quality as being more unacceptable to the child, while characteristics indicating a lack of parental investment and cooperation with the ingroup were more unacceptable to themselves. Sex differences between mothers and fathers and sons and daughters were explored.

The present research examined how a preference for influencing the mate choice of one's offspring is associated with opposition to out-group mating among parents from three ethnic groups in the Mexican state of Oaxaca: mestizos (people of mixed descent, n = 103), indigenous Mixtecs (n = 65), and blacks (n = 35). Nearly all of the men in this study were farmworkers or fishermen. Overall, the level of preferred parental influence on mate choice was higher than in Western populations, but lower than in Asian populations. Only among the Mixtecs were fathers more in favor of parental influence on the mate choice of children than mothers were. As predicted, opposition to out-group mating was an important predictor of preferred parental influence on mate choice, more so among fathers than among mothers, especially in the mestizo group-the group with the highest status. In addition, women, and especially mestizo women, expressed more opposition to out-group mating than men did. © 2012 Springer Science + Business Media, LLC.

Recent experimental results on the radiation generated from an electron beam passing closely over a conducting grating are presented. The most striking results are that the output power is 4 orders of magnitude more intense than that predicted by the Smith–Purcell explanation and that the output power increases exponentially with the beam thickness until it saturates at a thickness of a 1000 times the grating period. The recent theoretical model of Chang and McDaniel [Phys. Rev. Lett. 63, 1066 (1989); J. Opt. Soc. Am. B 7, 239 (1990)] is shown to compare favorably with these results.

In his commentary on the taxonomy of health systems and networks that we originally developed in Bazzoli et al. (1999) and updated through Dubbs et al. (2004), Luke raises various concerns about the underlying concepts, measures, and approaches we used to develop our classification scheme. His primary concerns are: (1) a bias in system assignment occurs because the taxonomy categories capture multimarket configurations of systems rather than centralization per se; (2) hospital service configuration data do not provide relevant information about the locus of health system/network decision making; (3) the conceptual framework used may not be relevant for health networks; and (4) measurement error exists in certain variables. We address each of these issues in this rejoinder. Before commenting on these points, we note that our primary purpose for developing the taxonomy in the late 1990s was to examine the structure and strategy of health networks and systems as the American Hospital Association (AHA) and others defined them. The AHA had a long history of tracking these organizations, collecting information on multihospital systems starting in the mid-1970s and on health networks beginning in 1993. Over time, the objectives and structure of these organizations changed in response to changing market imperatives. Most notable was the movement in the mid-1990s to develop organized delivery systems in anticipation of the Clinton administration's Health Security Act of 1994 and in response to the growing belief that capitated contracting between providers and health plans would become common. There was widespread acknowledgement among researchers and the industry that the organizations tracked by the AHA were growing more heterogeneous, and this led to concern that health services research that attempted to measure a system or network effect on hospital behavior would provide misleading information given the diversity of these organizations. This sparked our interest, and that of the Agency for Healthcare Research and Quality, which funded our research, in developing tools for researchers, the hospital industry, and policy makers so they could identify and examine more finely grained, homogenous groups of health networks and systems.

We do not agree with the interpretation and evaluation of our article by Voracek. We feel that our results and our interpretation of the results are supported by our data analyses and do add to the current understanding of the relationship between 2D:4D and personality. We feel confident we can address many, if not all, of Voracek's criticisms. However, we fully agree that 2D:4D research would benefit from more replication and from the use of larger sample sizes. © 2013 Wiley Periodicals, Inc. Language: en

A number of years ago a taxonomy of health networks and systems was created, using data from the mid-1990s, for the purpose of defining the structures and strategies of newly emerging health care organizations and identifying classes of health care organizations that share common features (Bazzoli et al. 1999). Since that time, the taxonomy has become a valuable tool not only for policymakers and practitioners, but also for health services researchers who have used it to address the performance of groups of health organizations that share similar characteristics (Bazzoli et al. 2000; Bazzoli et al. 2001; Carey 2003; Dubbs 2003; Lee Alexander and Bazzoli 2003; Rosko and Proenca 2003; Shortell, Bazzoli et al. 2000). The health care world, however, has changed a great deal since the mid-1990s and in order for a taxonomy of health networks and systems to continue to be useful, it must be periodically updated to assure it appropriately depicts the spectrum of current organizational configurations. When the initial taxonomy of health networks and systems was created, it reflected organizations' anticipation of continued strong momentum toward service and financial integration created by the prospects for national health care reform in 1994. By 1998, however, this momentum had slowed substantially. In addition, by the late 1990s, capitation trends had failed to unfold as anticipated, consumer backlash against managed care had intensified, merger activity had decreased, and vertical disintegration had begun to occur (Bazzoli et al. 2001; Lesser and Ginsburg 2000; Shortell, Gillies et al. 2000b). As organizational configurations shifted and members of health networks/systems realigned, the major categories of organizations identified in the taxonomy may have changed. As a first step toward understanding these changes, a longitudinal study of organizational trends from 1994 to 1998 was conducted using the original taxonomy categorization scheme (Bazzoli et al. 2001). In this work, significant shifts were found in the numbers of observations appearing in each organizational category, as well as a general shift whereby observations tended to go from the centralized categories to the more moderately centralized categories. Now, as a next step, the work described in this paper explores the possibility that, over time, there could be additional changes in organizational structure whereby 1998 networks/systems actually cluster into entirely new categories than they did five years ago. The objectives of this paper are to revisit the taxonomy of health networks and systems in order to: (a) assess how the original cluster categories of hospital-led health networks and systems have changed over time; (b) identify any new patterns of cluster configurations; and (c) demonstrate how additional data can be used to refine and enhance the taxonomy measures.

There has been much discussion of the appropriateness of various organizational strategies for today's healthcare industry. This article presents case studies of two healthcare organizations that have pursued very different configurations. PennCARE uses a virtually integrated, loose contract-based arrangement, while Henry Ford Health System employs a vertically integrated, tight ownership model. Despite these different approaches, their overall designs are strikingly similar. In essence both systems demonstrate a property called organizational design consistency; they simply approach it from different ends of the spectrum. This article presents the notion of organizational design consistency and defines it as the steady pursuit of a single preferred configuration strategy across key elements of organizational design. To illustrate the framework the case studies target four key elements of organizational design (governance structure, organizational culture, strategic planning processes, and decision-making procedures) and explain how consistency across these components adds value to both of these differently configured healthcare systems. There is room enough for diverse configurations of organizations in the current healthcare environment. Consistency does not mandate conformity; value can be derived from both tight and loose models. Furthermore, when fashioning organizational design consistency strategies, healthcare systems should carefully choose tightly or loosely modeled configurations to appropriately suit their aims, their markets, and the capabilities and resources available to them.

We present experimental investigations of Smith–Purcell radiation and Salisbury’s model and emphasize the amplification mechanism and efforts to build a resonator operating in the visible wavelength region. The first experiment demonstrated that electrons can be reflected from a rough surface owing to crystal-lattice diffraction. The second experiment showed that the radiation output increases exponentially as the beam thickness increases, indicating a possible occurrence of lasing action; the results were consistent with Salisbury’s model. The last experiment yielded inconclusive results; the use of a more stable electron beam and a blazed grating is suggested for future experiments.

We calculated seasonal accumulation of dry matter and crude protein in sainfoin and alfalfa and feed qualily at three stages of maturity when species were grown on irrigated and dryland. Maximum accumulation of dry matter and crude protein occurred between 2 and 45% bloom for alfalfa and at 100% bloom for sainfoin on irrigated land. Dry matter and crude protein yield trends for both crops were similar on irrigated land and dryland. The maximum dry matter and crude protein contents for both sainfoin and alfalfa occurred at about the same calendar date on dryland but at different dates under irrigation. Decreases in the percentage of crude protein were similar in both species with time. At all sampling dates crude protein percentage of alfalfa was greater than for sainfoin. At similar stages of maturity alfalfa was consistently higher than sainfoin in crude protein, ash, calcium, and crude fiber; and with few exceptions it was lower in nitrogen-free extract, total digestible nutrients, and P. At the point of maximum yield for each species (10% bloom for alfalfa, 100% bloom for sainfoin) crude fiber and total digestible nutrient content was similar, but alfalfa contained 6% more protein and 9 to 10% less nitrogen-free extract than sainfoin. We concluded that sainfoin hay would supply adequate protein to meet the needs of beef animals, and that it would supply total available energy equal or superior to that of alfalfa.