Influence of combined biotic and abiotic stress on nutritional quality parameters in tomato (Solanum lycopersicum)

Induction of abiotic stress in tomato plants has been proposed as a mechanism for improving the nutritional quality of fruits. However, the occurrence of biotic stress can interfere with normal abiotic stress responses. In this study, the combined effect of water stress and infection with plant-parasitic nematodes on the nutritional quality of tomato was investigated. Plants were exposed to one or both stresses, and the levels of phenolic compounds, carotenoids, and sugars in fruits were analyzed as well as physiological responses. Levels of carotenoids lycopene and β-carotene were lower in water-stressed tomatoes but exhibited a different response pattern under combined stress. Nematode stress was associated with increased flavonoid levels, albeit with reduced yields, while chlorogenic acid was increased by nematodes, water stress, and the combined stress. Sugar levels were higher only in tomatoes exposed to both stresses. These results emphasize the importance of studying plant stress factors in combination.     

Depolarization of alfalfa root hair membrane potential by Rhizobium meliloti Nod factors

Although much is known about the bacterial genetics of early nodulation, little is known about the plant cell response. Alfalfa root hair cells were impaled with intracellular microelectrodes to measure a membrane potential depolarizing activity in Rhizobium meliloti cell-free filtrates, a plant response dependent on the bacterial nodulation genes. The depolarization was desensitized by repeated exposure to factors and was not observed in a representative nonlegume. A purified extracellular Nod factor, NodRm-IV(S), caused membrane potential depolarization at nanomolar concentrations. This rapid single-cell assay provides a tool for dissecting the mechanisms of host cell response in early nodulation.     

Dynamical Signature of the Mott-Hubbard Transition in Ni(S,Se)2

The transition metal chalcogenide Ni(S,Se)2 is one of the few highly correlated, Mott-Hubbard systems without a strong first-order structural distortion that normally cuts off the critical behavior at the metal-insulator transition. The zero-temperature (T) transition was tuned with pressure, and significant deviations were found near the quantum critical point from the usual T1/2 behavior of the conductivity characteristic of electron-electron interactions in the presence of disorder. The transport data for pressure and temperature below 1 kelvin could be collapsed onto a universal scaling curve.     

Gaseous nitrate radical: possible nighttime atmospheric sink for biogenic organic compounds

The gaseous nitrate (NO(3)) radical, which has recently been measured in nighttime ambient atmospheres over the United States and Europe at concentrations up to approximately 350 parts per trillion, has now been shown to react rapidly with the biogenically emitted organic compounds dimethyl sulfide (DMS), isoprene, and several monoterpenes. Computer simulations demonstrate that these reactions can dominate the atmospheric behavior of these organic compounds at night. Thus reaction with NO(3) radicals may be the unknown, nonphotochemical removal process for DMS recently invoked by Andreae and Raemdonck to explain the absence of a diurnal profile for DMS in maritime air influenced by continental air masses. Similarly, the nighttime reaction of NO(3) radicals with monoterpenes can be a dominant removal process, leading to very low monoterpene concentrations in ambient atmospheres during the early morning.     

Strong, transparent, multifunctional, carbon nanotube sheets

Individual carbon nanotubes are like minute bits of string, and many trillions of these invisible strings must be assembled to make useful macroscopic articles. We demonstrated such assembly at rates above 7 meters per minute by cooperatively rotating carbon nanotubes in vertically oriented nanotube arrays (forests) and made 5-centimeter-wide, meter-long transparent sheets. These self-supporting nanotube sheets are initially formed as a highly anisotropic electronically conducting aerogel that can be densified into strong sheets that are as thin as 50 nanometers. The measured gravimetric strength of orthogonally oriented sheet arrays exceeds that of sheets of high-strength steel. These nanotube sheets have been used in laboratory demonstrations for the microwave bonding of plastics and for making transparent, highly elastomeric electrodes; planar sources of polarized broad-band radiation; conducting appliqués; and flexible organic light-emitting diodes.     

An Overview: Recycling Nutrients from Crop Residues For Space Applications

Without some form of regenerative life support system, long duration space habitation or travel will be limited severely by the prohibitive costs of resupplying air, water, and food from Earth. Components under consideration for inclusion in a regenerative life support system are based on either physicochemical or biological processes. Physicochemical systems would use filtration and elemental phase changes to convert waste materials into usable products, while biological systems would use higher plants and bioreactors to supply crew needs. Neither a purely biological nor strictly a physicochemical approach can supply all crew needs, thus, the best each approach can offer will be combined into a hybrid regenerative life support system. Researchers at Kennedy Space Center (KSC) Advanced Life Support Breadboard Project have taken the lead on bioregenerative aspects of space life support. The major focus has been on utilization of higher plants for production of food, oxygen, and clean water. However, a key to any regenerative life support system is recycling and recovery of resources (wastes). In keeping with the emphasis at KSC on bioregenerative systems and with the focus on plants, this paper focuses on research with biologically-based options for resource recovery from inedible crop residues.     

Studies on Sarcocystis species III: The macrocystic species of sheep

Three forms of macrocyst were studied in sheep. On the basis of their dimensions and cyst-wall ultrastructure, thin cysts were found to be a separate species from fat and oesophageal cysts, but were also transmitted by cats. Sporocysts derived from fat and thin cysts had similar dimensions. It is proposed that the thin species be named S. medusiformis n.sp.     

Investigating design and provision of access facilities as a barrier to woodland use

A key policy objective of many European Governments and their forestry departments is socially inclusive use of woodlands as use is a pre-requisite to enjoying many of the benefits afforded by woodland. However, access to woodlands is unequally distributed across British society and research suggests disconnect between the facilities provided and their suitability-for-use, given the wide range of reasons for visiting woodland. This research sought to inform woodland management and complement research into barriers to accessing woodland by investigating whether the design and provision of core access facilities may preclude certain user-groups. The research was carried out on the public forest estate of England; although the results are applicable to any woodland where public access is encouraged. The generic findings are applicable also to other greenspace types. Preferences in design were strongly influenced by the instrumentality (functionality) and aesthetic of an item – whether it was in-keeping with the woodland setting. Facility provision and upkeep are also important to woodland users. The study suggests that small changes in facility provision, including greater emphasis on naturalistic and rustic designs, provision of a range of pathway surface types and reducing the urbanisation of woodland, could increase the appeal of woodland to a wider demographic. Woodlands can fulfil a wide range of social functions. Where this is desirable, the woodland (new or existing) should be appropriately designed to reflect these intended roles and functions. This will require a range of facilities sympathetically provided.