How much carbon is stored in the terrestrial ecosystems of the Chilean Patagonia?

We estimated the amount of carbon (C) stored in terrestrial ecosystems of the Chilean Patagonia and the proportion within protected areas. We used existing public databases that provide information on C stocks in biomass and soils. Data were analysed by ecosystem and forest type in the case of native forests. Our results show that some ecosystems have been more extensively studied both for their stocks in biomass and soils (e.g. forests) compared with others (e.g. shrublands). Forests and peatlands store the largest amount of C because of their large stocks per hectare and the large area they cover. The total amount of C stored per unit area varies from 261.7 to 432.8 Mg C ha⁻¹, depending on the published value used for soil organic C stocks in peatlands, highlighting the need to have more precise estimates of the C stored in this and other ecosystems. The mean stock in national parks (508 Mg C ha⁻¹) is almost twice the amount stored in undisturbed forests in the Amazon. State and private protected areas contain 58.9% and 2.1% of the C stock, respectively, playing a key role in protecting ecosystems in this once pristine area.     

Temporal Hierarchies of Variation and the Maintenance of Diversity

Abstract A general model shows how the long-term growth rate of a population can be partitioned into components representing various mechanisms of maintenance of species diversity. One component summarises the effects of fluctuation-independent mechanisms, which include classical resource partitioning and frequency-dependent herbivory. Two other components represent fluctuation-dependent mechanisms, the storage effect and relative nonlinearity of competition.
The general model shows how a community will track an equilibrium set by fluctuation-independent mechanisms and the environmental state when community dynamics are faster than the rate of environmental change. Fluctuation-dependent mechanisms can be important for diversity maintenance with or without such tracking, but on long timescales their effects are indistinguishable from those of fluctuation-independent mechanisms.
These considerations lead to a hierarchical view of mechanisms of diversity maintenance where the effects of different timescales are partitioned or merged depending on the timescale of observation. These issues are illustrated with model examples involving various combinations of resource partitioning, fluctuations in recruitment rates, variation in the timing of germination, and seasonality. The very long timescales associated with climate change contain many complexities but nevertheless many ideas applicable to shorter timescales may be useful in a modified form.     

Loss of the actin regulator cyclase-associated protein 1 (CAP1) modestly affects dendritic spine remodeling during synaptic plasticity

Dendritic spines form the postsynaptic compartment of most excitatory synapses in the vertebrate brain. Morphological changes of dendritic spines contribute to major forms of synaptic plasticity such as long-term potentiation (LTP) or depression (LTD). Synaptic plasticity underlies learning and memory, and defects in synaptic plasticity contribute to the pathogeneses of human brain disorders. Hence, deciphering the molecules that drive spine remodeling during synaptic plasticity is critical for understanding the neuronal basis of physiological and pathological brain function. Since actin filaments (F-actin) define dendritic spine morphology, actin-binding proteins (ABP) that accelerate dis-/assembly of F-actin moved into the focus as critical regulators of synaptic plasticity. We recently identified cyclase-associated protein 1 (CAP1) as a novel actin regulator in neurons that cooperates with cofilin1, an ABP relevant for synaptic plasticity. We therefore hypothesized a crucial role for CAP1 in structural synaptic plasticity. By exploiting mouse hippocampal neurons, we tested this hypothesis in the present study. We found that induction of both forms of synaptic plasticity oppositely altered concentration of exogenous, myc-tagged CAP1 in dendritic spines, with chemical LTP (cLTP) decreasing and chemical LTD (cLTD) increasing it. cLTP induced spine enlargement in CAP1-deficient neurons. However, it did not increase the density of large spines, different from control neurons. cLTD induced spine retraction and spine size reduction in control neurons, but not in CAP1-KO neurons. Together, we report that postsynaptic myc-CAP1 concentration oppositely changed during cLTP and cTLD and that CAP1 inactivation modestly affected structural plasticity.     

Work at cold storage

1. 1. Work activities in cold storage rooms were assessed by a mailed questionnaire survey of cold storage facilities in Japan.

2. 2. There are nearly 4000 cold storage facilities and about 80% are being kept at temperatures below −20°C.

3. 3. The chief items of stock in storage were marine products, livestock products, frozen food and agricultural products.

4. 4. Methods used for loading and unloading in cold storage rooms are forklift, manual handling, and automatic machines.

5. 5. Use of forklifts appeared to be widespread.

6. 6. Working time differed according to the ambient temperature of the cold storage rooms.

7. 7. Common ailments of cold storage workers are lumbago, bronchitis, neuralgia etc.

In situ localization of faba bean and oat legumin-type proteins in transgenic tobacco seeds by a highly sensitive immunological tissue print technique

We have used a highly sensitive immunological tissue print technique to study cell- and tissue-specific expression of heterologous genes in transgenic plants. Primary polyclonal antibodies, raised against legumin of faba bean (Vicia faba L.) and 12S globulin of oat (Avena sativa L.) were used to localize these proteins in transgenic tobacco seeds in a streptavidin-alkaline phosphatase assay in combination with biotinylated secondary antibodies producing a higher sensitivity (by several amplification steps) of the assay. Both storage protein genes were found to be expressed in a specific pattern. While legumin is preferentially accumulated in certain parts of the embryo, the oat legumin-type globulin is restricted to the endosperm. The applied technique is highly sensitive with a resolution power down to the singlecell level and allows rapid screening of large numbers of samples.     

Long-termin vitro storage ofColocasia esculenta under minimal growth conditions

The storage of a clone ofColocasia esculenta at 28/24°C over a 12-h photoperiod in the absence of mannitol, was not feasible with transfer intervals of more than eight months. Mannitol had a positive effect on survival at this temperature, but caused abnormalities at high concentrations. At 9°C in total darkness,C. esculenta could be stored for more than eight years with transfer intervals of approximately three years. After this period, more than 90% of the cultures showed living shoots, but not all shoots per culture showed regrowth. Cultures which were transferred three times during the experimental period, had a significantly (=0.05) lower number of regrowing shoots than cultures which were transferred twice. This might be due to the fact that the former cultures were transferred at a less favourable developmental stage. The addition of mannitol to the storage medium did not improve survival and regrowth, nor did a more gradual lowering of the temperature to 9°C.     

PRODUCTION OF HYALINE HAIRS BY INTERTIDAL SPECIES OF FUCUS (FUCALES) AND THEIR ROLE IN PHOSPHATE UPTAKE1

A field study to determine the precise times of year at which three intertidal species of Fucus start to produce hyaline hairs and cease producing such hairs was conducted on the Isle of Man, U.K. Hairs were first observed during February, and within 6 days of their initial appearance, all tagged plants of all species at all tidal heights on the shore possessed hairs. Hair production continued until the beginning of October, at which time Fucus plants growing at the lowest stations (+ 3.0 m) had glabrous apical growth. Hair production continued later into the year for plants growing higher on the shore, and it was not until mid-November that glabrous apical growth was observed in all plants. Phosphate uptake rates of pilose (hairy) and glabrous (hairless) apical sections were measured in November 1988 for F. spiralis L. and in January 1989 for F. spiralis and F. serratus L., at phosphate concentrations ranging from 0.8 μM (ambient seawater) to 9.0 μM. In ambient seawater, pilose plants of F. spiralis removed phosphate 2–3 times faster than glabrous plants, whereas the uptake rates of pilose plants of F. serratus were about 50% greater than those of glabrous plants. The differences between uptake rates of pilose and glabrous plants of both species were smaller or nonsignificant at higher phosphate concentrations. The field and laboratory data are consistent with the hypothesis that hairs are formed in Fucus as a response to increased nutrient demand and that hairs facilitate the uptake of nutrients from seawater at concentrations typical of natural situations.     

Medium-term conservation of mature embryos of coconut

Optimal conditions for the medium-term conservation of zygotic embryos of coconut were developed. After 6 months of storage on a medium devoid of sucrose and containing 2 g l^–1 activated charcoal, 100% of the embryos developed into whole plantlets within 5 months after transfer to the recovery medium. After a 12-month storage period on medium containing 15 g l^–1 sucrose and devoid of activated charcoal, 51% of the embryos germinated within 2 months after transfer to the recovery medium.     

Caste specialization in food storage in the dimorphic antColobopsis nipponicus (Wheeler)

Summary Food-storage abilities of both minor and major workers of the dimorphic antColobopsis nipponicus were examined to prove the hypothesis that major workers of this species have a trophic role in addition to a defensive one. Both worker subcastes accumulated water, that was supplied with water-soluble food, as well as fat, that probably originated from food given. However, the major workers accumulated much larger amounts of water and fat than did the minor workers. Difference in water accumulation increased as food supply increased. In spite of their difference in body weight, the residual amount of fat after starvation did not differ between the two subcastes. Although the amount of stored fat increased with colony size in both subcastes, the stored fat per dry weight of the major worker was significantly larger than that of the minor worker regardless of the colony size. When workers of a colony were starved, minor workers with a single major worker survived significantly longer than those without a major worker. In addition, about half the behavioral acts of major workers were regurgitation for minor workers. These results demonstrate that major workers ofC. nipponicus functioned as a trophic caste. On the basis of the results, quantitative relationships of storage abilities between the two worker subcastes are discussed.