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Thousands of years before the maize-based agriculture practiced by many Native American societies in eastern North America at the time of contact with Europeans, there existed a unique crop system only known through archaeological evidence. There are no written or oral records of how these lost crops were cultivated, but several domesticated subspecies have been identified in the archaeological record. Growth experiments and observations of living progenitors of these crops can provide insights into the ancient agricultural system of eastern North America, the role of developmental plasticity in the process of domestication, and the creation and maintenance of diverse landraces under cultivation. In addition, experimental gardens are potent tools for public education, and can also be used to conserve remaining populations of lost crop progenitors and explore the possibility of re-domesticating these species.

The timing, geographical locations, causes, and consequences of crop domestication have long been major concerns of archaeologists, and agricultural origins and dispersals are currently more relevant than ever to scientists seeking solutions to elusive problems involving food insecurity and global health disparities. Perennial research issues that archaeologists continue to tackle include (1) thinking outside centers of origin that were based on limited and insufficient past knowledge; (2) distinguishing between single and multiple domestications of specific crops; (3) measuring the pace of domestication; and (4) decoupling domestication from agricultural economies. Paleoethnobotanists have expanded their toolkits to include analysis of ancient and modern DNA and have added increasingly sophisticated techniques in the field and the laboratory to derive precise chronological sequences to assess morphological changes in ancient and often fragmentary archaeobotanical remains and to correctly interpret taphonomy and context. Multiple lines of archaeological evidence are ideally brought together, and whenever possible, these are integrated with information from complementary sources. We discuss current perspectives and anthropological approaches to research that have as their goals the fuller and broader understanding of ancient farming societies, the plants that were domesticated, the landscapes that were created, and the culinary legacies that were passed on., (© 2014 Botanical Society of America, Inc.)

Our understanding of the initial period of agriculture in the southwestern United States has been transformed by recent discoveries that establish the presence of maize there by 2100 cal. B.C. (calibrated calendrical years before the Christian era) and document the processes by which it was integrated into local foraging economies. Here we review archaeological, paleoecological, linguistic, and genetic data to evaluate the hypothesis that Proto-Uto-Aztecan (PUA) farmers migrating from a homeland in Mesoamerica introduced maize agriculture to the region. We conclude that this hypothesis is untenable and that the available data indicate instead a Great Basin homeland for the PUA, the breakup of this speech community into northern and southern divisions approximately 6900 cal. B.C. and the dispersal of maize agriculture from Mesoamerica to the US Southwest via group-to-group diffusion across a Southern Uto-Aztecan linguistic continuum.

The hygiene hypothesis postulates that the increase in atopic diseases may in part be due to diminished exposure to microorganisms. But it is unknown which type of infection does render protection. An epidemiological study was conducted in Leipzig, Germany, and its rural county, involving 3347 school starters. Two types of infection were considered: (1) gastrointestinal colonisation (Helicobacter pylori detection using in vivo [(13)C] urea breath test) and (2) respiratory infections (physician-diagnosed lower (bronchitis) and upper (common cold) respiratory infections). H pylori colonisation was selected because it is very common and plays an important role in gastrointestinal disorders. Atopic eczema was selected as the (allergic) target variable because of its high frequency in the age of the study participants. The results, adjusted for relevant confounders, showed a significant inverse association between H pylori infection and eczema (adjusted odds ratio (aOR) = 0.31, p = 0.006) in children not predisposed to atopy. In contrast, bronchitis increased the risk of eczema (aOR = 1.98, p<0.001). Bacterial digestive tract colonisation (infection) seems to protect against eczema in comparison with the effect of respiratory tract infections. The hygiene hypothesis may be better explained when gastrointestinal and respiratory infections are subtly differentiated.

Background: Other factors besides a genetic disposition seem to play a role in the development of allergic disorders. Exposure to risk factors such as indoor air pollution is becoming increasingly interesting, especially during early childhood., Methods: Within an epidemiological study (LISS: Leipzig infection, allergy and airway diseases study among school starters, involving 2536 children, birth cohort 1991/92, carried out in 1997/98) the effect of indoor exposure on physician-confirmed eczema and allergic symptoms has been investigated. The exposure situation has been characterized on hand of the redecoration activities (painting, floor covering and new furniture) before birth and in the first years of life., Results: Highly exposed children showed a significant effect on allergic disorders. The lifetime prevalences without any vs. all three redecoration activities were for allergic symptoms 9.3% vs. 17.2% and for eczema 11.5% vs. 20.4%. Adjusted for confounders, the redecoration associated burden led to odds ratios of 1.8 (95% CI: 1.3-2.6) for allergic symptoms and 1.9 (95% CI: 1.4-2.7) for eczema., Conclusion: Exposure emissions due to redecoration activities seem to be associated with the risk of eczema and allergic symptoms. Thus, prevention of allergic disorders should include the avoidance of such activities around birth and in the first year of life.

Helicobacter pylori (H. pylori) is one of the world's most widespread microorganisms. Its acquisition in humans remains poorly understood, however, epidemiological studies have identified drinking water as reservoir for the bacterium. The aim of this study was to investigate the prevalence of H. pylori infection among individuals using or drinking previously H. pylori tested well water. Applying household cluster sampling, a total of 91 subjects, all using or drinking well water (13 of either H. pylori positive or negative wells), were screened for their H. pylori status. The group was comprised of 73 adults and 19 children under the age of 18. H. pylori infection was determined using the [13C]urea breath test. A self-administered or parent-completed questionnaire provided information on living conditions and lifestyle habits including the use or drinking of well water. Logistic regression analyses associated the drinking of H. pylori positive well water with a positive colonization status [Odds Ratio (OR) 8.3; 95% confidence interval (95% CI) 2.4-29]. In summary, the use or drinking of H. pylori contaminated well water appears associated with the acquisition of a H. pylori infection. This study is based on a relatively small and inhomogeneous population sample and should be repeated to confirm the results.

Background: Studies conducted in Europe as well as in North and South America have tried to link Helicobacter pylori colonization with the drinking water supply, especially since H. pylori is known to survive quite well in water., Methods: In 2000, a cohort of 1884 grade-two children from two rural counties surrounding the city of Leipzig, Germany (77.4% of the 1991/1992 birth cohort) were tested for H. pylori colonization using the [13C]urea breath test. A parent-completed questionnaire elicited details on living conditions and lifestyle habits including questions on the children's drinking water from sources other than public water supplies, swimming in natural waters, etc. In a second independent study, samples of well water, taken from 157 private wells still used in the two counties, were being tested for the presence of H. pylori, using polymerase chain reaction (PCR) method to determine relevant target DNA fragments of H. pylori., Results: In county I, 5.7% of the children and in county II 6.6% tested H. pylori-positive. Cluster analyses of the questionnaire data in both counties pointed to 'drinking water from other than municipal sources', as the closest H. pylori-associated cluster variable. The cluster estimations were supported by odds ratio (OR) calculations with an OR=16.4 (95% confidence interval (CI) 3.1,...,88.5) for county I and OR=4.0 (95% CI 1.3,...,12.4) for county II. The PCR analyses showed H. pylori DNA fragments in 10.8% of the wells in county I and 9.2% in county II. The detection limit was set at 10 DNA copies corresponding to 125 bacteria/L, the average infestation of these wells was 931 bacteria/L., Conclusion: Despite the fact that the microbiological and epidemiological data do not correspond except that both studies were conducted in the same geographical areas, the independent findings of H. pylori in well water in the same general areas where children do seem to drink water other than from the public water supply suggests that water may be an important source of H. pylori infection.

Asthma is of increasing concern especially in industrialized countries. This cross-sectional study was to assess the influence of spatial and temporal variations in the urban air pollution profile on asthmatic disease. The prevalences presented are based on physician-diagnosed asthmatic and allergic disease data, collected between 1993 and 1995. Seven hundred and thirty-six preschool children (age 2 to 7, mean 5.7 years) of 37 daycare centres in the City of Leipzig participated in the study. Variations were observed in the lifetime prevalences of asthma and allergy with differences in a residential area's ambient pollution profile. Depending on the level of traffic (high or low), children residing in areas with a dominant coal-heating emission profile had more frequently a diagnosis of asthma, 17.5% and 8.8% (95% confidence intervals [CI]: 10.8...23.5 and 5.8...11.6, respectively), as compared to those, living in centrally heated areas 13.4% and 5.8% (CI: 6.6...19.3 and 1.2...9.6, respectively). Allergic disorders occurred more often in areas with a predominantly traffic-associated pollution profile, 14.3% and 9.6% vs. 5.8% and 3.7% (CI: 7.4...20.3 and 6.4...12.5; 1.2...9.6 and 0.2...6.5, respectively). Interestingly, asthmatic disease was not necessarily associated with a clinical history of allergies. Of the children with physician-diagnosed asthma, 83.7% were not reported to have a concurrent diagnosis of allergies nor to show clinical symptoms. This suggests that environmental exposures (i.e., complex pollution mixtures associated with residential coal-heating and/or traffic) may have differentially influenced the phenotypic expression of asthma. A qualitative discussion is presented on the occurrence of "asthma without reported allergies" in Leipzig.

A panel of 277 children, aged 3-7 years, was used to study the association between air pollution (O(3), SO(2), NO(2), and total suspended particles), meteorological factors (global radiation, maximum daytime temperature, daily averages of vapour pressure and air humidity) and respiratory symptoms. For 759 days the symptoms were recorded in a diary and modelling was based on a modification of the method proposed by Korn and Whittemore (Biometrics 35: 795-798, 1979). This approach (1) comprises an extension using environmental parameters at different time scales, (2) addresses the suitability of using the daily fraction of symptomatic individuals to account for inter-individual interactions and (3) enables the most significant weather effects to be identified. The resulting model consisted of (1) an individual specific intercept that takes account of the population's heterogeneity, (2) the individual's health status the day before, (3) a long-term meteorological effect, which may be either the squared temperature or global radiation in interaction with temperature, (4) the short-term effect of sulfur dioxide, and (5) the short-term effect of an 8-h ozone concentration above 60 microg/m(3). Using the estimated parameters as input to a simulation study, we checked the quality of the model and demonstrate that the annual cycle of the prevalence of respiratory symptoms is associated to atmospheric covariates. Individuals suffering from allergy have been identified as a group of a particular susceptibility to ozone. The duration of respiratory symptoms appears to be free of scale and follows an exponential distribution function, which confirms that the symptom record of each individual follows a Poisson point-process. This supports the assumption that not only respiratory diseases, but also respiratory symptoms can be considered an independent measure for the health status of a population sample. Since a point process is described by only one parameter (namely the intensity of the point process), it is appropriate for records of respiratory symptoms to identify only one model which covers both the occurrence and duration of symptoms.

In 1998, the Helicobacter pylori [(13)C]urea breath test was offered to all school beginners (birth cohort 1991/1992) in the city of Leipzig and in Leipzig County, Germany, to determine the colonization prevalence and potential transmission pathways of the bacterium. A total of 3,347 school beginners participated in the test, and 2,888 parents completed the detailed, self-administered questionnaire. The H. pylori prevalence was 6.5% [95% confidence interval (CI), 5.3-7.6] in the city and 5.7% (CI, 4.2-7.0) in the county. Using cluster analysis (WARD's method, Euclidean distances), we identified different sets of variables (confirmed by multivariate logistic regression analyses [odds ratios (ORs)] that are signficantly associated with H. pylori positivity. Among city children, the risk is significantly increased with contact to a pet hamster (OR = 2.4; 95% CI, 1.2-4.7; p < 0.015) and travels to Asian countries (OR = 3.7; 95% CI, 1.6-8.7; p < 0.002). Among county children, H. pylori positivity increased significantly with drinking of water from nonmunicipal sources (OR = 16.4; 95% CI, 3.1-88.5; p < 0.001), more than 3 children living in a household (OR = 4.2; 95% CI, 1.2-14.6; p < 0.02), and contact with pet hamsters (OR = 2.4; 95% CI, 1.0-5.7; p < 0.04). These data suggest that, in a general population sample, indirect fecal-oral transmission and living conditions are important risk factors in the spread of H. pylori infection. However, clinical symptoms do not necessarily indicate H. pylori positivity.

Epidemiologic evidence indicates that respiratory disease in infancy and childhood has respiratory health consequences in later life. Pulmonary function is considered a good index of early effects. This study assessed the relationship of pulmonary function in preschool children in Leipzig, Germany, and exposure to high levels of air pollution during early childhood. Spirometric measures were taken of 235 preschoolers (126 boys, 109 girls, mean age 5.1 +/- 1.3 years) attending 16 randomly selected daycare centres, using the 'Bosch Spiro 501' spirometer. The results showed decrements in the average FVC (85.5% predicted [pred]) and FEV1 (90.2% pred) differing with spatial variations in the ambient air pollution burden of the children's residential area. Exposure to a pollution profile of heavy traffic and/or domestic heating showed markedly lower FVC (78.9% and 85.5% pred, respectively) and FEV1 (82.4% and 88.5% pred). Miller's Diagnostic Quadrant Model of Disease Classification, categorizing pulmonary function data for preliminary diagnostic purposes, assessed the lung function values (FVC% pred/relative FEV1 [FEV1/FVC]%) of a significant number of children as 'restrictions' (n = 52; 22.1%). Summarizing: variations in spirometric indices were observed across exposure groups with a significant number of children showing signs of a restrictive ventilatory function. These cross-sectional data, however, do not permit to conclude with any degree of certainty that this is indicative of an early sign of a functional deficit.

Etiolated maize (Zea mays L.) seedlings were grown in the dark for 5 days in an atmosphere enriched with 10.0 atom% (18)O(2). Hydroxyproline was isolated from root and shoot tissues, purified, and methylated. It was not possible to determine (18)O incorporation into hydroxyproline by conventional mass spectrometry because the final product was not sufficiently pure. The final product was analyzed successfully by tandem mass spectrometry. The (18)O content of the hydroxyl oxygen atom was 10 +/- 0.7 atom%. This result demonstrates that the hydroxyl oxygen atom in hydroxyproline was derived exclusively from molecular oxygen.

Mesophyll cells and bundle sheath strands were isolated rapidly from leaves of the C(4) species Digitaria pentzii Stent. (slenderstem digitgrass) by a chopping and differential filtration technique. Rates of CO(2) fixation in the light by mesophyll and bundle sheath cells without added exogenous substrates were 6.3 and 54.2 micromoles of CO(2) per milligram of chlorophyll per hour, respectively. The addition of pyruvate or phosphoenolpyruvate to the mesophyll cells increased the rates to 15.2 and 824.6 micromoles of CO(2) per milligram of chlorophyll per hour, respectively. The addition of ribose 5-phosphate increased the rate for bundle sheath cells to 106.8 micromoles of CO(2) per milligram of chlorophyll per hour. These rates are comparable to those reported for cells isolated by other methods. The K(m)(HCO(3) (-)) for mesophyll cells was 0.9 mm; for bundle sheath cells it was 1.3 mm at low, and 40 mm at higher HCO(3) (-) concentrations. After 2 hours of photosynthesis by mesophyll cells in (14)CO(2) and phosphoenolpyruvate, 88% of the incorporated (14)C was found in organic acids and 0.8% in carbohydrates; for bundle sheath cells incubated in ribose 5-phosphate and ATP, more than 58% of incorporated (14)C was found in carbohydrates, mainly starch, and 32% in organic acids. These findings, together with the stimulation of CO(2) fixation by phosphoenolpyruvate for mesophyll cells and by ribose 5-phosphate plus ATP for bundle sheath cells, and the location of phosphoenolpyruvate and ribulose bisphosphate carboxylases in mesophyll and bundle sheath cells, respectively, are in accord with the scheme of C(4) photosynthesis which places the Calvin cycle in the bundle sheath and C(4) acid formation in mesophyll cells.Starch and reducing sugars were present in both mesophyll and bundle sheath cells following a period of photosynthesis by whole leaves. However, when isolated cells were exposed to (14)CO(2) in the light, even with appropriate exogenous substrates, only bundle sheath cells accumulated appreciable amounts of labeled carbohydrates. Incubation of mesophyll cells in the light with ATP and either pyruvate and inorganic phosphate, or phosphoenolpyruvate, or 3-phosphoglycerate resulted in large increases in total carbohydrates. The 3-phosphoglycerate treatment produced the greatest increase. These results could not be explained on the basis of increased CO(2) fixation. They suggest that mesophyll cells are able to metabolize exogenously supplied 3-carbon compounds to carbohydrates, despite the apparent inability of these cells to utilize CO(2) for this purpose, and support the view that in the whole leaf 3-phosphoglycerate is transported from bundle sheath to mesophyll cells, where it is reduced to carbohydrate.Sucrose and sucrose-phosphate synthetases and invertase were localized mainly in bundle sheath cells. ADP-Glucose starch synthetase and amylase were present mainly in bundle sheath cells whereas starch phosphorylase was present mainly in mesophyll cells.

Etiolated maize and soybean seedlings were grown for several days in atmospheres enriched with O(18). Hydroxyproline subsequently isolated from the seedlings by column and thin-layer chromatography was labeled with excess O(18), but proline was not. Control experiments in which seedlings were grown in H(2)O(18) and unlabeled atmospheres demonstrated that neither proline nor hydroxyproline was labeled with excess O(18). It was concluded that oxygen fixation is an essential feature of hydroxyproline biosynthesis in these seedlings, and that the hydroxyl oxygen atom in hydroxyproline is derived from molecular oxygen and not from water; similar results have been reported previously for sycamore cell suspensions.