Natural Cure

Chips on the left are from potatoes infected with the zebra chip disease, which alters the sugar levels and causes the sugar to carmelize and give a burned appearance, according to Dr. Don Henne, Texas AgriLife Research assistant research scientist.

Credit: (Texas AgriLife Research photo by Kay Ledbetter)
Dr. Don Henne isn't wasting his degree when he's standing by the deep fryer waiting for potato slices to turn brown. He's conducting research that will help the potato industry and consumers.

Henne, an assistant research scientist in the Texas AgriLife Research plant pathology program in Amarillo, is one of a number of who are trying to find answers about zebra chip. Zebra chip is the latest disease to plague the potato industry, particularly those in the chipping business.

Dr. Charlie Rush, AgriLife Research plant pathologist and leader of the program, began working on the project at the request of local producers in early 2007. His work later became a part of the Zebra Chip State Initiative through the Texas Department of Agriculture.

The initiative brought together scientists from throughout the state and country to try to find answers for zebra chip, Rush said.

"When we first began working on it, the pathogen and vector were unknown," he said. "Only recently have scientists began pinning those down".

Rush said Henne was brought into the program in May because of his experience and background. His primary responsibility is to help understand the factors that impact disease onset and spread. Zebra chip is a disease that alters the sugar levels in the potato, Henne said. The sugar caramelizes and turns the chip brown when it is fried, giving it an off taste and burnt appearance. While it is not harmful, it is a cosmetic and taste concern for consumers.

Potato growers have had to abandon entire infected fields, costing as much as $2 million a year in damage, he said.

Henne, who has a degree in entomology, is trying to chase the potato psyllid, the insect that likely carries the pathogens which cause the disease. He is trying to find out what makes it move through a field, as well as when it moves and how fast.

He has visited grower fields from Weslaco to Pearsall and Olton to Dalhart already this year, as well as made contact with other zebra chip scientists around the nation to familiarize himself with this new chipping potato disease.

Zebra chip first appeared in Mexico and Guatemala in the early 2000s. It has been found in potato fields through South Texas and the Rio Grande Valley and now up into the South Plains and Panhandle regions.

The disease presents itself as curled leaves and stunted growth in the plant itself, and then the tubers exhibit a brown striped or mottled pattern when sliced, Henne said.

AgriLife Research and other researchers around the country have studied the vector or insect that transmits the pathogen, he said. Others are trying to identify the pathogen or bacteria that actually causes disease in the plant when the psyllid feeds on it.

Henne and other Amarillo-based scientists are working with commercial growers to monitor the movement of the insect and disease appearance. At the same time, they have established potato plots at the Texas AgriLife Research Station at Bushland and are doing some greenhouse work.

"We're focusing on the epidemiological aspects of the disease," Henne said. "We are trying to understand how the disease progresses in a potato field over time. We are looking at canopy structure, edge effect and how the insects are landing in fields and distributing the disease".

Henne and Dr. Fekede Workneh, an AgriLife Research quantitative plant disease epidemiologist, have planted six acres of potatoes at the Bushland station where they are looking at planting dates, canopy structure and insect dispersal.

Potatoes are planted in late March to early June in the Panhandle, so they are experimenting with planting dates May 2, May 28 and June 16 at Bushland to see if there is a relation between insect movement and disease severity.

"We are also working in the lab to graft diseased portions onto healthy plants to understand the movement of the disease through the plant," Henne said.

"We want to understand how the disease progresses so we can focus management practices on specific areas," he said. "Do the insects move up the plant, down or out from the stem? Some varieties have more canopy than others and is that acting as a natural bridge for insect movement?".

There is no adequate control for the insect or the disease at this time, he said.

Because there are other diseases that have similar symptoms as zebra chip, Henne said, one of the challenges they face is being able to correctly identify diseased plants in the field.

"When we find plants that appear to be infected, we bring the tubers back to the lab where they are sliced and fried to make the final determination," he said.

Henne said they hoped to have some management suggestions on how to help alleviate the problem for growers by the end of this year.


Posted by: Evelyn    Source

Scientists at the University of Minnesota have discovered a gene that may provide a clue as to why obesity rates increase with age. The research was published recently in the Proceedings of the National Academy of Sciences
Scientists in the lab of Kevin Wickman, Ph.D., associate professor of pharmacology at the University of Minnesota Medical School, removed a single gene from mice as part of a research study that's ongoing to understand how the brain controls heart function. While some cardiac deficiencies were detected in these mice, the scientists unexpectedly observed that these mice exhibited a predisposition to adult-onset obesity.

"This was not an outcome we expected, but now we have an animal model that may provide new insight into human obesity," said Wickman, co-author of the article.

By examining closely where this gene, termed Girk4, is expressed in the body, the scientists found especially high levels in the hypothalamus, a brain region involved in regulating food intake and energy expenditure. Wickman speculated that disruption of normal function in the hypothalamus may underlie the obesity seen in the mutant mice, but he acknowledges that more studies are needed to understand where and how this gene works, and consequently, why mice missing this gene develop obesity.

The age-dependence of the obesity seen in this mouse model mimics human obesity patterns, scientists said. Indeed, the likelihood of people developing obesity more than doubles between the ages of 20 and 60.

"This is a novel finding that may provide important new insight to the underlying cellular mechanisms that influence obesity," said Catherine Kotz, Ph.D., co-author of the article, scientist at the Minneapolis VA Medical Center and adjunct professor in the Department of Food Science and Nutrition at the University of Minnesota.


Posted by: Evelyn    Source

Healthy individuals who gain weight, even to a weight still considered normal, are at risk for developing chronic kidney disease (CKD), as per a research studyappearing in the September 2008 issue of the Journal of the American Society Nephrology (JASN). The study suggests that CKD should be added to the list of conditions that are linked to weight gain, including diabetes and hypertension.

Research has shown that obesity is associated with an increased risk of CKD, but no studies have looked at the effects of weight gain within the "normal" range of an individual's body mass index. To investigate, Drs. Seungho Ryu and Yoosoo Chang of the Kangbuk Samsung Hospital in Seoul, Korea, and their colleagues conducted a prospective study of individuals who were of a healthy weight and had no known risk factors for chronic kidney disease.

In Korea, all workers participate in either annual or biennial health exams, as mandatory by Korea's Industrial Safety and Health Law. As a result, the researchers had access to clinical data from thousands of individuals. For this study, they included 8,792 healthy men who participated in the health exams in 2002.

The scientists discovered a U-shaped association between weight change and development of CKD. Men who lost or gained a lot of weight (more than 0.75 kg per year) had the highest risk of developing CKD. Those whose weight changed minimally (within a range of -0.25 to

Women who gain more or less than recommended amounts of weight during pregnancy are likely to increase the risk of problems for both themselves and their child, as per a new report by the RTI International-University of North Carolina at Chapel Hill Evidence-based Practice Center.

The report, which was supported by the U.S. Department of Health and Human Services Agency for Healthcare Research and Quality (AHRQ) in partnership with the American Dietetic Association, is based on a systematic review of 150 studies that assessed the short- and long-term effects of maternal weight gain on pregnancy, mothers, fetuses, and children. The studies were published in English between January 1990 and October 2007.

Among the reports key findings is a strong association between high maternal weight gain and increased fetal growth and infant birth weight, which can contribute to complications during labor if a baby is too big, and can lead to long term health effects for the child. High maternal weight gain also is linked to cesarean delivery and weight retention by mothers after childbirth.

The review also confirmed that gaining too little weight during pregnancy can be a problem. Low maternal weight gain is linked to poor fetal growth, lower birth weight, and the chance of a baby being born prematurely.

The report was prompted by several trends, including an increase in the number of American women who are overweight and obese, as well as the number who gain more weight during pregnancy than amounts laid out in the Institute of Medicines 1990 recommendations for maternal weight gain. Public health officials also are concerned about an increase in pregnancy complications such as diabetes and cesarean delivery.

The Institute of Medicine is currently reviewing its pregnancy weight guidelines to see if they need to be revised; it expects to issue a report next summer.

Unfortunately, the existing body of research on maternal weight gain is inadequate to permit a more comprehensive assessment, said Meera Viswanathan, Ph.D., the study director and a senior research analyst at RTI International. Most beneficial would be an analysis that considers the risks and potential benefits of various maternal weight-gain scenarios to all women irrespective of age, race or ethnicity, or their body mass index before they became pregnant. But such an analysis is not possible at this time.

Her research colleague at UNC, Anna Maria Siega-Riz, Ph.D., agreed.

Despite the large body of research, clear clinical recommendations based on this systematic review will be challenging to formulate because of major shortcomings in this research, said Siega-Riz, an associate professor in the UNC School of Public Healths epidemiology and nutrition departments. To fully understand the effects of maternal weight gain on short- and long-term health outcomes for both women and infants, future studies will need to adopt standard measures and consistent definitions of exposures and outcomes.

The scientists said future studies will need to examine multiple outcomes within the same study population to explore fully the trade-offs between the risks and benefits to the mother and to the child.


Posted by: Evelyn    Source

Tejate What the Long, Strange Trip of Tejate, a Maize-based Mexican Drink, reveals about a Worldwide Agricultural System at a Crossroads.

Michael Pollan's recent bestseller The Omnivore's Dilemma revealed to millions of readers the centrality, and dangers, of commodity corn in the modern industrialized agriculture system as developed in the United States. The "modern varieties" of corn, which are low in diversity, are now taking over the very birthplace of the crop, Southern Mexico, where it is known as maize. In their paper for the new issue of Current Anthropology, "Food Globalization and Local Diversity: The Case of Tejate, a Traditional Maize and Cacao Beverage from Oaxaca, Mexico" authors Daniela Soleri, David Cleveland, and Flavio Aragon-Cuevas trace the unique history of the ancient drink, and show how it could be the harbinger for the future of agriculture and food variety. In this indigenous drink is contained a central irony of globalization, for the very set of forces that threaten to destroy tejate may in the end save both the drink and the diverse varieties of maize.

Southern Mexico, tejate's birthplace, holds an august position in the history of agriculture. In addition to maize, three species of squash, chile, common bean, and avocado were domesticated here. Traditional "farmers' varieties" of crops have met an enormous challenge in the worldwide "Green Revolution" (launched in Mexico, incidentally) of the twentieth century, which brought down food prices, but at the cost of crop diversity-including among maize varieties. The modern varieties of maize have already won out in the commercial production of tortillas, among other staples. Traditional foods that continue to require the more diverse tastes and qualities of farmers' varieties are the only bulwark against the extinction of those varieties and their globally important genetic diversity. Tejate, the drink of work, parties, festivities, and family meals in Oaxaca, remains linked to the maize harvest, and has remained the domain of traditional farmers' varieties of maize. Through field work in two communities in Oaxaca, Soleri and her co-authors observed that tejate is in its steepest decline in the modern community, where maize diversity and traditional foods are also waning. The more traditional community, conversely, makes tejate more often and maintains a wider diversity of maize types for this and other traditional foods.

Immigration patterns, however, complicate what might seem yet another sad tale of globalization overwhelming traditional culture. The scientists observed that residents of more traditional communities were more likely to immigrate to larger Mexican cities or the United States. As a result, there is now a demand for tejate in Los Angeles, and in Mexican cities, where commercial tejateras take over the time-consuming task. While some ingredients, such as seeds from the mamey tree, are acquired from Oaxaca, the maize and the ash needed to process it are acquired domestically, often through unique channels. The authors interview a Los Angeles-based tejatera and find that she prepares her batches from.

fifty pounds of maize bought from the neighborhood pet store as whole grain bird feed! Ashes for making cuanestle are bought from a fast food chain that produces wood-barbequed chicken. Pizle, cacao, and rosita de cacao are sent to her by her family from Oaxaca via a courier service, and she uses a metate and mano carried to her from Oaxaca by a family member.

As a result of immigration, a nascent and informal international trade has helped preserve tejate's more exotic ingredients, but the fate of traditional varieties of maize remains inconclusive. Will tejate follow tortillas and become a less flavorful, industrialized version of its former self......or will its arrival in wealthier cities create a wider demand for a gourmet, traditional version? Soleri, Cleveland, and Aragon-Cuevas conclude that tejate will serve as a harbinger for the direction of food variety, and that "whether globalization will ultimately support, enhance, or diminish the biological and cultural diversity on which tejate is based, and which it reinforces, will depend on the confluence of a number of different forces, and simple generalizations are inappropriate." Either way, anyone interested in the future of food would be wise to follow the case of the foamy drink from one of the cradles of agriculture.

About the Authors......Daniela Soleri is a Research Scientist in the Geography Department at the University of California-Santa Barbara. David A. Cleveland is Associate Professor of Environmental Studies at the University of California-Santa Barbara. Flavio Aragon-Cuevas is a Senior Plant Genetic Resources Specialist with the Instituto Nacional de Investigaciones Forestales y Agropecuarias, in Oaxaca, Mexico.


Posted by: Evelyn    Source