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Fucoxanthin is a major light-harvesting pigment in ecologically important algae such as diatoms, haptophytes, and brown algae (Phaeophyceae). Therefore, it is a major driver of global primary productivity. Species of these algal groups are brown colored because the high amounts of fucoxanthin bound to the proteins of their photosynthetic machineries enable efficient absorption of green light. While the structure of these fucoxanthin-chlorophyll proteins has recently been resolved, the biosynthetic pathway of fucoxanthin is still unknown. Here, we identified two enzymes central to this pathway by generating corresponding knockout mutants of the diatom Phaeodactylum tricornutum that are green due to the lack of fucoxanthin. Complementation of the mutants with the native genes or orthologs from haptophytes restored fucoxanthin biosynthesis. We propose a complete biosynthetic path to fucoxanthin in diatoms and haptophytes based on the carotenoid intermediates identified in the mutants and in vitro biochemical assays. It is substantially more complex than anticipated and reveals diadinoxanthin metabolism as the central regulatory hub connecting the photoprotective xanthophyll cycle and the formation of fucoxanthin. Moreover, our data show that the pathway evolved by repeated duplication and neofunctionalization of genes for the xanthophyll cycle enzymes violaxanthin de-epoxidase and zeaxanthin epoxidase. Brown algae lack diadinoxanthin and the genes described here and instead use an alternative pathway predicted to involve fewer enzymes. Our work represents a major step forward in elucidating the biosynthesis of fucoxanthin and understanding the evolution, biogenesis, and regulation of the photosynthetic machinery in algae.

Small proteins are a new and expanding area of research. Many characterized small proteins are composed of a single hydrophobic α-helix, and the functional requirements of their limited amino acid sequence are not well understood. One hydrophobic small protein, CydX, has been shown to be a component of the cytochrome bd oxidase complex in Escherichia coli, and is required for enzyme function. To investigate small protein sequence specificity, an alanine scanning mutagenesis on the small protein CydX was conducted using mutant alleles expressed from the E. coli chromosome at the wild-type locus. The resulting mutant strains were assayed for CydX function. No single amino acid was required to maintain wild-type resistance to β-mercaptoethanol. However, substitutions of 10-amino acid blocks indicated that the N-terminus of the protein was required for wild-type CydX activity. A series of double mutants showed that multiple mutations at the N-terminus led to β-mercaptoethanol sensitivity in vivo. Triple mutants showed both in vivo and in vitro phenotypes. Together, these data provide evidence suggesting a high level of functional plasticity in CydX, in which multiple amino acids may work cooperatively to facilitate CydX function.

The number of small proteins (SPs) encoded in the Escherichia coli genome is unknown, as current bioinformatics and biochemical techniques make short gene and small protein identification challenging. One method of small protein identification involves adding an epitope tag to the 3' end of a short open reading frame (sORF) on the chromosome, with synthesis confirmed by immunoblot assays. In this study, this strategy was used to identify new E. coli small proteins, tagging 80 sORFs in the E. coli genome, and assayed for protein synthesis. The selected sORFs represent diverse sequence characteristics, including degrees of sORF conservation, predicted transmembrane domains, sORF direction with respect to flanking genes, ribosome binding site (RBS) prediction, and ribosome profiling results. Of 80 sORFs, 36 resulted in encoded synthesized proteins-a 45% success rate. Modeling of detected versus non-detected small proteins analysis showed predictions based on RBS prediction, transcription data, and ribosome profiling had statistically-significant correlation with protein synthesis; however, there was no correlation between current sORF annotation and protein synthesis. These results suggest substantial numbers of small proteins remain undiscovered in E. coli, and existing bioinformatics techniques must continue to improve to facilitate identification.

Renaissance England's Chief Rabbi: John Selden, by Jason P. Rosenblact. New York: Oxford University Press, 2006. 314 pp. $99.00. The impact of Greek and Latin scholarship upon English Renaissance culture continues to be examined intensely, but apart from studies of the King James Bible and Milton, little concerted attention has been devoted to the contribution of Hebrew studies to that culture. Hence the exceptional importance of Jason Rosenblatts new study: Renaissance England's Chief Rabbi: John Seiden, a work deploring and correcting that neglect. Rosenblatt s volume swirls around Seiden, but is more broadly dedicated to "the cultural influence of rabbinic and especially talmudic scholarship on some early modern British poets and intellectuals as mediated principally by Seiden" (p. 3). The sweep of the volume is large. Rosenblatt opens with the divorce proceedings of Henry VIII. Lacking adequate rabbinic authorities in England, Henry sent inquiries to Jewish scholars abroad concerning incest laws and critical biblical texts concerning levirate marriage. This discussion illuminates the impoverished state of Hebrew studies at the outset of the English Renaissance and the curious responses of the rabbis themselves, and likewise shows how an understanding of that theological controversy leads to a richer understanding of Hamlet. From that point, Rosenblatt focuses upon Seiden's intense exploration of rabbinic and Talmudic material and the impact of his studies upon a wide spectrum of English figures, ranging from Ben Jonson to Sir John Vaughan Among English intellectuals of his rime, only Seiden placed "rabbinic thought at the centre of his scholarship" (p. 105). The focus of Rosenblatt's study is thus two-fold: (1) the character and direction of Selden's explorations of rabbinic wisdom; and (2) his transmission of that learning to his friends and to his culture at large. Rosenblatt documents that Selden's fascination with rabbinic materials was already well advanced by the time of the writing of De Diis Syris (1617) (p. 2), and Seiden continued to explore these materials until the end of his life, producing six substantial works resting upon that scholarship. By the time of his death in 1654, Rosenblatt affirms, "Seiden would have been the most learned rabbinic scholar in the country," an accomplishment leading one Christian Hebraist in 1641 to address him as "Rabbi" (p. 4). Selden's reputation, moreover, as the most learned man in England led students of every stripe to pore over his volumes, to such an extent that he in essence became a primary text himself, the study of Seiden generally substituting for the study of the actual rabbinic works. Once Selden's influence weakened, tellingly, so did the quality of Hebrew learning itself in England. As important as the study of Hebrew texts themselves, however, was Selden's orientation. Rosenblatt shows that Selden's rabbinic works "constitute a notable exception to those products of the English Renaissance that emphasize otherness and difference" (p. 161). "In the midst of an age of prejudice," he insists, "Seiden transmitted an uncommonly generous view of Judaism" (p. 9). So influential were Selden's views, in fact, that Rosenblatt argues that his promulgation of ideas drawn from ancient writers as well as post-Talmudic rabbis created conditions leading to the reintroduction of Jews into England in the 1650s (pp. 277-8). Such is the larger portrait of Seiden. The chapters themselves have a divided emphasis. The first half of the volume brings rabbinic learning (largely mediated by Seiden) to bear on literary matters. Selden's learned correspondence with Ben Jonson over the issue of cross-dressing is particularly interesting, as are Rosenblatt's two chapters detailing Selden's influence upon Milton's creations. …

To identify the sources of disseminated Mycobacterium avium complex (MAC) infection in AIDS.HIV positive subjects with CD4 counts100/mm(3) in Atlanta, Boston, New Hampshire and Finland were entered in a prospective cohort study. Subjects were interviewed about potential MAC exposures, had phlebotomy performed for determination of antibody to mycobacterial lipoarabinomannin and for culture. Patient-directed water samples were collected from places of residence, work and recreation. Patients were followed for the development of disseminated MAC. Univariate and multivariate risk factors for MAC were analyzed.Disseminated MAC was identified in 31 (9%) subjects. Significant risks in univariate analysis included prior Pneumocystis carinii pneumonia (PCP) (hazard ratio 1.821), consumption of spring water (4.909), consumption of raw seafood (34.3), gastrointestinal endoscopy (2.894), and showering outside the home (0.388). PCP, showering and endoscopy remained significant in a Cox proportional hazards model. There was no association between M. avium colonization of home water and risk of MAC. In patients with CD425, median OD antibody levels to lipoarabinomannin at baseline were 0.054 among patients who did not develop MAC and 0.021 among patients who did develop MAC (P=0.077).MAC infection results from diverse and likely undetectable environmental and nosocomial exposures. Mycobacterial infection before HIV infection may confer protection against disseminated MAC in advanced AIDS.

BACKGROUND: Graduated driver licensing (GDL) requirements aim to reduce the incidence of motor vehicle crashes and crash-related fatalities for novice drivers by limiting their exposure to the most risky driving situations. These programs vary across states in their scope, intensity, and impact. The purpose of this study was to evaluate the short-term impact of the 2009 Arkansas GDL on reducing teen crashes and fatal crashes. METHODS: Arkansas motor vehicle crash data for 2008 and 2010 were compared. Changes in rates per 10,000 licensed drivers were calculated by age, during the night restriction, and for drivers with passengers. χ analyses were used to test significant differences in rates between pre- and post-GDL years for each age group. RESULTS: Significant decreases in crash rates were found for each age group younger than 19 years, with the largest change evident for 16-year-olds (reduction of 22%). Similar decreases were not found for adults 19 years and older. Rates of fatal crashes for 14- to 18-year-olds were reduced 59%. Nighttime crashes and crashes in vehicles driven by teens with more than one unrelated passenger also demonstrated reductions. CONCLUSION: This study provides evidence of a short-term impact of GDL restrictions on reducing teen driver crashes and fatal crashes in Arkansas. Findings for teen drivers were significantly different from those of adult drivers during the same time frame, further strengthening the results as a function of GDL restrictions as compared with alternative explanations. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level V. Language: en

Vitamin intakes of 255 toddlers (aged 18-30 mo) were estimated from food consumption recorded during 1 y at sites in Egypt, Kenya, and Mexico. Mean intakes were compared with requirements standards by using a probability approach to estimate the prevalence of inadequate intakes. There were predicted inadequacies for vitamin A (32%) and riboflavin (20%) in Egypt, vitamins A (68%) and C (63%) and riboflavin (52%) in Mexico, and vitamin B-12 (44%) in Kenya. Vitamin E was inadequate in all diets, but in relation to polyunsaturated fatty acids only the intake in Mexico was low. No diet provided the recommended amount of vitamin D, but its dietary requirement is uncertain. Correlations among nutrient intakes suggest factors that may contribute to reported associations of consumption of animal products with improved growth or development among these children: provision of vitamin B-12 and available minerals, displacement of fiber and phytate-rich energy sources, and increased energy density.Data on 255 children, 18-30 months old, in Kalama village on the Nile delta in Egypt, the Embu district in Kenya, and the Solis Valley in Mexico were analyzed over a 1-year period to study the relationships of energy and animal protein intakes with vitamins, minerals, and two factors that affect bioavailability, dietary fiber and phytate. The researchers used the probability approach to determine the prevalence of inadequate intakes. Estimated intake inadequacies were 32% for vitamin A and 20% for riboflavin in Egypt; 68% for vitamin A, 63% for vitamin C, and 52% for riboflavin in Mexico, and 44% for vitamin B12 in Kenya. All the diets were deficient in vitamin E. Yet, when researchers compared vitamin E in relation to polyunsaturated fatty acids, the vitamin E intake was low only in Mexico. None of the diets had the recommended amount of vitamin D, but actual dietary requirements were unknown. Further, the researchers had no information on solar exposure. Provision of vitamin B12 and available minerals, displacement of fiber and phytate-rich energy sources, and increased energy density were associated with improved growth or development among children ingesting animal products (p 0.05). Intakes of folacin, niacin, and thiamin were negatively related to animal protein intake (p 0.05).

Health care workers and medical students in the United States subject to annual tuberculin skin testing.To use skin testing with Mycobacterium avium sensitin (MAS) to determine contemporary rates of infection with non-tuberculous mycobacteria (NTM) and their effect on reactions to M. tuberculosis purified protein derivative (PPD).Dual skin testing was performed with PPD and MAS on 784 health care workers and medical students in the northern and southern US. MAS reactions that wereor = 5 mm and alsoor = 3 mm larger than the PPD reaction were defined as MAS dominant and due to NTM.MAS reactions wereor = 5 mm in 40% andor = 15 mm in 18% of subjects; 95% were MAS dominant. MAS dominant reactions were more common in the south than the north (P0.001). PPD reactions wereor = 15 mm in 3% of subjects. PPD reactionsor = 15 mm were more common among males, foreign born subjects and subjects with BCG immunization (all P0.001). MAS dominant reactions were found in 82% of subjects with 5-9 mm PPD reactions and 50% with 10-14 mm PPD reactions; these reactions were more common among whites (P = 0.046), US-born (P = 0.038) and subjects without BCG immunization (P = 0.004).Infections with NTM are responsible for the majority of 5-14 mm PPD reactions among US-born health care workers and medical students subject to annual tuberculin testing.

The association between living arrangement and dietary quality of older U.S. adults was investigated in 4,402 adults aged 55 years or older who participated in the Nationwide Food Consumption Survey, 1977 to 1978. Dietary quality was based on percent of Recommended Dietary Allowances for 3-day intakes of nine nutrients. More men living alone consumed a poor-quality diet than did men living with a spouse, particularly those 75 years or older; for women, this effect was seen only in the 55- to 64-year-old group. In general, more women than men had poor-quality diets. A number of factors (economic, employment, health status, energy intake, body mass index, and nutrient supplement use) were examined for their importance in accounting for differences in dietary quality of older men and women living alone compared with those living with a spouse. Energy intake was the most important variable accounting for the association of living arrangement with dietary quality. Evidence indicated that older adults living alone did not make poorer food choices than those living with a spouse, but rather that they consumed fewer calories.

Immunoglobulin levels were studied in the genital secretions of seven heifers which had been bred to a bull infected with Mycoplasma agalactiae var. bovis and three heifers bred to a noninfected bull. The median immunoglobulin G (IgG)/IgA ratio ratio for vaginal secretions was 0.7, for cervical secretions 21.9, and for uterine secretions 13.0. This indicated that IgA was the mahor immunoglobilin class in the most superficial portion of the reproductive tract and that IgG was the major class in secretions of the deeper tract. The response to infection was studied by comparing animals infected with mycoplasma and noninfected controls. The IgG/IgA ratios were significantly lower in infected animals than in controls, apparently due to high IgA values in infected animals. Low mycoplasmal agglutinin titers were detected in secretions of three of the infected animals, but there appeared to be no relationship between agglutinin titers and histopathological lesions or between agglutinin titers and IgG/IgA ratios in this group of animals.

When Izaak Walton presented his Life of Mr. George Herbert as a 'Freewill- offering: he provided a clue to its character. The other biographies, he would have us believe, he had been compelled to write, some to honour the obligations of friendship, others to comply with the entreaties of men he respected and revered. All the early biographies were thus biographies of duty. But here was one of inner compulsion, a 'free-will offering' in the full sense of the term — an unsolicited giving to the church. And for this offering Walton mustered all his art, as if to demonstrate what biography in his hands could now achieve. He still worried about truth and fidelity to fact; but no longer did he worry about his 'artless pen.' When he wrote the Life of Herbert he knew he was a craftsman. As a result, the final version of this Life, so natural in presentation, has a subtlety of artistic manipulation far exceeding any of his earlier efforts. To appreciate its perfection, however, we need to unravel its strands, for the special quality of the biography springs from the deft interweaving of the life pattern of George Herbert with the personal vision of Izaak Walton on the nature of holy living.'

Variation in canine gestation length was studied in a Beagle colony (n = 290) in which apparent gestation length, estimated as the interval from the day of first mating to the day of parturition, ranged from 57 to 72 days, and averaged 65.3 +/- 0.2 days. The interval from the day of the peak in luteinizing hormone (LH) to parturition was less variable and ranged from 64 to 66 days and averaged 65.1 +/- 0.1 days (n = 54). Apparent gestation lengths less than or equal to 61 days all resulted from mating greater than or equal to 3 days after the LH peak; those greater than or equal to 68 days all followed initial or single matings occurring greater than or equal to 2 days before the LH peak. Fertile single matings 3 days before the LH peak provided evidence that the potential postcoital fertile longevity of canine sperm is at least 6 days and thus contributed, along with variability in the onset of estrus, to the observed variation in apparent gestation length in the dog. The limited range in the interval from the day of the preovulatory LH peak to the day of parturition (64, 65, or 66 days) demonstrates a considerable regularity in the sequential events of gestation in the dog.

THE NUMBER OF SOULS in Ireland being usually reckoned one Million and a half," muses the persona of A Modest Proposal, "of these I calculate there may be about Two hundred Thousand Couple whose Wives are Breeders."' The computation itself is not novel. Swift had offered the same estimate several years earlier in the second of the Drapier's Letters (1724): "Now by the largest Computation (even before that grievous Discouragement of Agriculture, which hath so much lessened our Numbers) the Souls in this Kingdom are computed to be One Million and a half; which, allowing Six to a Family, makes Two Hundred and Fifty Thousand Families" (X, 16). Swift had also used the figure in a tract he never published, A Letter on Maculla's Project About Halfpence & a New One Proposed (1729): "They have been reckoned at a million and a half, whereof a million at least are beggars, in all circumstances, except that of wandering about for alms" (XII, 99).2 The last passage is especially valuable, for it strongly attests to Swift's belief in the integrity of the tally. Yet for the student of Swift and of Irish economic history, the interest of this calculation lies in its enormous inaccuracy.3 That very inaccuracy, however, permits us to sketch Swift's position in a

SURELY IT IS ODD that Donne's Satyre II has not attracted more serious attention. It was written before he entered Egerton's service, probably soon after his brother died as a result of the official persecution of missionary priests and during the very period when Donne was closeted with Beza and Bellarmine as well as studying law. The poem begs for consideration if only to evaluate Donne's efforts to measure his experience during that early, vital period.' Careful study has been deflected, however, by a derogatory critical tradition concerning the poem. A typical reaction is that of Richard Hughes, who dismisses the poem eagerly, contrasting its "deficiencies" with a control he admires in Satyre I. He is so disappointed, in fact, that he considers the proposition that the poem antedates Satyre I. The fear that Donne stumbled could thus be exorcized by the argument of chronological development. The poem, Hughes claims, is merely stuffed with oddments which Donne could not accommodate in an earlier sat