The distribution of the most favorable temperatures for citrus flower induction in Israel

In this study the distribution of optimum temperatures for the induction of citrus blossoms in Israel has been determined. The number of flowers that form on citrus plants grown in the subtropics is known to be affected by the temperatures to which the plants are exposed. However, too few records of hourly temperatures exist in Israel to make an estimate of the occurrence and/or distribution of temperatures beneficial for citrus flower induction, although maximum and minimum temperatures are widely recorded. Thus, a model derived from the hourly records could be applied to the stations recording only maximum and minimum temperatures. The average optimum temperature was mapped for citrus flower induction throughout Israel.     

Psiscan: a computational approach to identify H/ACA-like and AGA-like non-coding RNA in trypanosomatid genomes

Background  

Detection of non coding RNA (ncRNA) molecules is a major bioinformatics challenge. This challenge is particularly difficult when attempting to detect H/ACA molecules which are involved in converting uridine to pseudouridine on rRNA in trypanosomes, because these organisms have unique H/ACA molecules (termed H/ACA-like) that lack several of the features that characterize H/ACA molecules in most other organisms.     

Pathological factors underlying hyperthermia

Hyperthermia is the result of an imbalance between total heat (metabolic heat and environmental heat) accumulated in the body and heat loss from the body, and is defined as a condition when core temperature rises above its normal range. This article will present an overview of syndromes associated with hyperthermia, through discussion of the etiology and pathophysiologic mechanisms that underlie those disorders. Emphasis will also be placed on the therapeutic measures to be taken in order to avert the complications of these disorders.     

Large fluxes of fatty acids from membranes to triacylglycerol and back during N-deprivation and recovery in Chlamydomonas

Microalgae accumulate triacylglycerol (TAG) during nutrient deprivation and break it down after nutrient resupply, and these processes involve dramatic shifts in cellular carbon allocation. Due to the importance of algae in the global carbon cycle, and the potential of algal lipids as feedstock for chemical and fuel production, these processes are of both ecophysiological and biotechnological importance. However, the metabolism of TAG is not well understood, particularly the contributions of fatty acids (FAs) from different membrane lipids to TAG accumulation and the fate of TAG FAs during degradation. Here, we used isotopic labeling time course experiments on Chlamydomonas reinhardtii to track FA synthesis and transfer between lipid pools during nitrogen (N)-deprivation and resupply. When cells were labeled before N-deprivation, total levels of label in cellular FAs were unchanged during subsequent N-deprivation and later resupply, despite large fluxes into and out of TAG and membrane lipid pools. Detailed analyses of FA levels and labeling revealed that about one-third of acyl chains accumulating in TAG during N-deprivation derive from preexisting membrane lipids, and in total, at least 45% of TAG FAs passed through membrane lipids at one point. Notably, most acyl chains in membrane lipids during recovery after N-resupply come from TAG. Fluxes of polyunsaturated FAs from plastidic membranes into TAG during N-deprivation were particularly noteworthy. These findings demonstrate a high degree of integration of TAG and membrane lipid metabolism and highlight a role for TAG in storage and supply of membrane lipid components.

In Chlamydomonas, about a third of triacylglycerol (TAG) made during nitrogen deprivation is derived from preexisting membranes, and most membranes made after resupply are derived from TAG.     

Interfacial pH during mussel adhesive plaque formation

Mussel (Mytilus californianus) adhesion to marine surfaces involves an intricate and adaptive synergy of molecules and spatio-temporal processes. Although the molecules, such as mussel foot proteins (mfps), are well characterized, deposition details remain vague and speculative. Developing methods for the precise surveillance of conditions that apply during mfp deposition would aid both in understanding mussel adhesion and translating this adhesion into useful technologies. To probe the interfacial pH at which mussels buffer the local environment during mfp deposition, a lipid bilayer with tethered pH-sensitive fluorochromes was assembled on mica. The interfacial pH during foot contact with modified mica ranged from 2.2 to 3.3, which is well below the seawater pH of ~ 8. The acidic pH serves multiple functions: it limits mfp-Dopa oxidation, thereby enabling the catecholic functionalities to adsorb to surface oxides by H-bonding and metal ion coordination, and provides a solubility switch for mfps, most of which aggregate at pH ≥ 7–8.     

Thigmomorphogenesis: The Involvement of Auxin and Abscisic Acid in Growth Retardation Due to Mechanical Perturbation

When young bean plants are mechanically perturbed for up to10 days, they accumulate large amounts of an auxin-like substanceand increased amounts of ABA. Exogenous ethylene, applied inthe form of ethephon, produces the same result. Physiologicallymoderately high amounts of exogenously applied IAA or loweramounts of ABA cause the same sort of retardation of elongationthat is caused by either mechanical perturbation or exogenousethephon. Either mechanical perturbation or applied ethephonsignificantly retards the polar basipetal transport of ¹⁴C-IAAIt is proposed that mechanical perturbation of bean internodesinduces ethylene evolution which, in turn, induces the accumulationof high levels of IAA and the production of ABA, both of whichcontribute to the retardation of elongation of the internodes. (Received December 24, 1981; Accepted May 19, 1982)     

The niche-width variation hypothesis reconfirmed: Validation by genetic diversity in the sessile intertidal cirripedes Chthamalus stellatus and Euraphia depressa (Crustacea,Chthamalidae)

Genetic diversity in a pair of cirripede species, based on electrophoretic analysis of 25 gene loci, is higher for Chthamalus stellatus, the species with a broader biogeographical distribution, and hence, with a broader ecological niche, than that of Euraphia depressa. Comparing the genetic diversity within E. depressa we again report a higher genetic diversity among the specimens exposed to solar radiation (living in the wider ecological niche) versus the specimens confined to the sheltered dark environments in caves or under boulders. The indices of genetic diversity used in this study are polymorphism, heterozygosity, mean number of alleles per locus and gene diversity. We conclude that the niche-width variation hypothesis has been confirmed in this pair of species: genetic diversity is positively correlated with niche breadth.     

Higher,Stronger, Better…︁ A Review of 5 Volt Cathode Materials for Advanced Lithium‐Ion Batteries

The ever‐increasing demand for high‐performing, economical, and safe power storage for portable electronics and electric vehicles stimulates R&D in the field of chemical power sources. In the past two decades, lithium‐ion technology has proven itself a most robust technology, which delivers high energy and power capabilities. At the same time, current technology requires that the energy and power capabilities of Li‐ion batteries be ‘beefed up’ beyond the existing state of the art. Increasing the battery voltage is one of the ways to improve battery energy density; in Li‐ion cells, the objective of current research is to develop a 5‐volt cell, and at the same time to maintain high specific charge capacity, excellent cycling, and safety. Since current anode materials possess working potentials fairly close to the potential of a lithium metal, the focus is on the development of cathode materials. This work reviews and analyzes the current state of the art, achievements, and challenges in the field of high‐voltage cathode materials for Li‐ion cells. Some suggestions regarding possible approaches for future development in the field are also presented.