Variability in the yield of benzophenanthridine alkaloids in wildcrafted vs cultivated bloodroot (Sanguinaria canadensis L.)

Populations of bloodroot [Sanguinaria canadensis L. (Papaveraceae)] are found throughout the eastern forests of North America, with particular abundance in the southern Appalachian Mountains. Increasingly, it is finding use in Europe as a nonantibiotic animal feed supplement to promote weight gain. As efforts to cultivate this herb are underway, there is a need to understand the effect of agronomic permutations on both the dry mass rhizome yield and the yield of benzophenanthridine alkaloids. Month-to-month variability of the concentration of the alkaloids sanguinarine and chelerythrine in both cultivated and wildcrafted bloodroot was examined. The alkaloid yield was consistently higher, but more variable, in wildcrafted plants. On average, cultivated rhizomes were both larger and more consistently sized than those that were wildcrafted. The concentration of a suite of trace elements was measured in soil that was collected concomitantly with each plant accession. Differences in element profiles were compared against alkaloid yields.     

Equine Metabolic Syndrome

Equine metabolic syndrome (EMS) is important because of its association with laminitis. Obesity and insulin resistance are two important components of EMS, and the underlying cause of this syndrome is likely to be enhanced metabolic efficiency. Affected horses are often referred to as “easy keepers” because they require fewer calories to maintain body condition, and enhanced metabolic efficiency is an inherent risk factor for EMS that may be genetically determined. Pony breeds, Morgan horses, and Paso Finos are predisposed to EMS, but this problem can be prevented through effective management. Overfeeding, abundant pasture grass, and inadequate exercise are risk factors that relate to modern management practices. Obesity and adiposity induce insulin resistance, and recent research suggests that this is the determinant of laminitis susceptibility in ponies. Increased plasma insulin concentrations are detected in most affected horses and ponies, so this serves as a useful screening test for EMS. Physical characteristics also should be examined because horses with EMS exhibit regional adiposity in the form of a cresty neck or abnormal adipose tissue deposits close to the tailhead. All horses with enhanced metabolic efficiency, obesity, or regional adiposity should be screened for EMS. The combined intravenous glucose−insulin test can be performed to diagnose insulin resistance in mildly affected horses and quantify insulin sensitivity. Most horses with EMS can be effectively managed by reducing caloric intake, decreasing the starch and sugar content of the diet, increasing exercise, and limiting or eliminating access to pasture, but medical therapy is warranted in select cases.     

精氨酸营养(二) 结合专业知识,利用精氨酸提高猪的生产性能

在一个真的国际性跨学科和由各方人士(营养师、生物学家、政府官员和饲料公司相关人员)参与的营销效能(marketing effort 市场效能)研究中,日粮添加剂将妊娠母猪和哺乳母猪的生产性能提高到了一个令人惊讶的水平.     

Titan's magnetic field signature during the first Cassini encounter

The magnetic field signature obtained by Cassini during its first close encounter with Titan on 26 October 2004 is presented and explained in terms of an advanced model. Titan was inside the saturnian magnetosphere. A magnetic field minimum before closest approach marked Cassini's entry into the magnetic ionopause layer. Cassini then left the northern and entered the southern magnetic tail lobe. The magnetic field before and after the encounter was approximately constant for approximately 20 Titan radii, but the field orientation changed exactly at the location of Titan's orbit. No evidence of an internal magnetic field at Titan was detected.     

Upper mantle discontinuity topography from thermal and chemical heterogeneity

Using high-resolution stacks of precursors to the seismic phase SS, we investigated seismic discontinuities associated with mineralogical phase changes approximately 410 and 660 kilometers (km) deep within Earth beneath South America and the surrounding oceans. Detailed maps of phase boundary topography revealed deep 410- and 660-km discontinuities in the down-dip direction of subduction, inconsistent with purely isochemical olivine phase transformation in response to lowered temperatures. Mechanisms invoking chemical heterogeneity within the mantle transition zone were explored to explain this feature. In some regions, multiple reflections from the discontinuities were detected, consistent with partial melt near 410-km depth and/or additional phase changes near 660-km depth. Thus, the origin of upper mantle heterogeneity has both chemical and thermal contributions and is associated with deeply rooted tectonic processes.     

Rap1 GTPase regulation of adherens junction positioning and cell adhesion

Cell-cell junctions are distributed evenly around the lateral circumference of cells within an epithelium. We find that the even distribution of adherens junctions is an active process that requires the small guanosine triphosphatase Rap1. Cells mutant for Rap1 condensed their adherens junctions to one side of the cell. This disrupted normal epithelial cell behavior, and mutant cell clones dispersed into the surrounding wild-type tissue. Rap1 is enriched at adherens junctions, particularly between newly divided sister cells where it may reseal the adherens junction ring. The regulation of adherens junction positioning could play a role in cell mobility and cell division.