Relative importance of transpiration rate and leaf morphological traits for the regulation of leaf temperature

Urban greening solutions such as green roofs help improve residents’ thermal comfort and building insulation. However, not all plants provide the same level of cooling. This is partially due to differences in plant structure and function, including different mechanisms that plants employ to regulate leaf temperature. Ranking of multiple leaf/plant traits involved in the regulation of leaf temperature (and, consequently, plants’ cooling ‘service’) is not well understood. We therefore investigated the relative importance of water loss, leaf colour, thickness and extent of pubescence for the regulation of leaf temperature, in the context of species for semi-extensive green roofs. Leaf temperature were measured with an infrared imaging camera in a range of contrasting genotypes within three plant genera (Heuchera, Salvia and Sempervivum). In three glasshouse experiments (each evaluating three or four genotypes of each genera) we varied water availability to the plants and assessed how leaf temperature altered depending on water loss and specific leaf traits. Greatest reductions in leaf temperature were closely associated with higher water loss. Additionally, in non-succulents (Heuchera, Salvia), lighter leaf colour and longer hair length (on pubescent leaves) both contributed to reduced leaf temperature. However, in succulent Sempervivum, colour/pubescence made no significant contribution; leaf thickness and water loss rate were the key regulating factors. We propose that this can lead to different plant types having significantly different potentials for cooling. We suggest that maintaining transpirational water loss by sustainable irrigation and selecting urban plants with favourable morphological traits is the key to maximising thermal benefits provided by applications such as green roofs.

Germination rate and sporeling development of Chondracanthus chamissoi (Rhodophyta, Gigartinales) varies along a latitudinal gradient on the coast of Chile

Chondracanthus chamissoi (C. Agardh) Kutzing is an economically important red seaweed with an extended latitudinal distribution along the south-east Pacific. Here we report on the seasonal in vitro germination of carpospores and tetraspores from four populations distributed from 27 to 41 degrees S on the Chilean coast. Our results show that both types of spores exhibited a different physiological behavior related to the geographic origin of the specimens. Germination occurred throughout the year for both spore types in the four populations. However, for the northern locations (Calderilla, La Herradura and Puerto Aldea) germination was higher in spring, while for the southern location (Lechagua), germination was higher in summer. The growth rate of carposporelings and tetrasporelings varied seasonally in ail locations studied, with higher growth in spring. Among all, carposporelings from Lechagua specimens reached the highest growth rates (9.3 +/- 0.2% d(-1)). However, spores from Herradura and P. Aldea had a good germination and SGR in all seasons and would be good candidates to start spores-based cultivation of this valuable resource in Chile. (C) 2009 Elsevier B.V. All rights reserved

The impact of fragmentation and density regulation on forest succession in the Atlantic rain forest

The Atlantic Rain Forest, an important biodiversity hot spot, has faced severe habitat loss since the last century which has resulted in a highly fragmented landscape with a large number of small forest patches (<100 ha). For conservation planning it is essential to understand how current and future forest regeneration depends on ecological processes, fragment size and the connection to the regional seed pool. We have investigated the following questions by applying the forest growth simulation model FORMIND to the situation of the Atlantic Forest in the state of Sao Paulo, SE Brazil: (1) which set of parameters describing the local regeneration and level of density regulation can reproduce the biomass distribution and stem density of an old growth forest in a reserve? (2) Which additional processes apart from those describing the dynamics of an old growth forest, drive forest succession of small isolated fragments? (3) Which role does external seed input play during succession? Therefore, more than 300 tree species have been classified into nine plant functional types (PFTs), which are characterized by maximum potential height and shade tolerance. We differentiate between two seed dispersal modes: (i) local dispersal, i.e. all seedlings originated from fertile trees within the simulated area and (ii) external seed rain. Local seed dispersal has been parameterized following the pattern oriented approach, using biomass estimates of old growth forest. We have found that moderate density regulation is essential to achieve coexistence for a broad range of regeneration parameters. Considering the expected uncertainty and variability in the regeneration processes it is important that the forest dynamics are robust to variations in the regeneration parameters. Furthermore, edge effects such as increased mortality at the border and external seed rain have been necessary to reproduce the patterns for small isolated fragments. Overall, simulated biomass is much lower in the fragments compared to the continuous forest, whereas shade tolerant species are affected most strongly by fragmentation. Our simulations can supplement empirical studies by extrapolating local knowledge on edge effects of fragments to larger temporal and spatial scales. In particular our results show the importance of external seed rain and therefore highlight the importance of structural connectivity between regenerating fragments and mature forest stands. (C) 2009 Elsevier B.V. All rights reserved.

T3 acutely increases GH mRNA translation rate and GH secretion in hypothyroid rats

Cytoskeleton controls the stability of transcripts, by mechanisms that involve mRNAs and eEF1A attachment to it. Besides, it plays a key role in protein synthesis and secretion, which seems to be impaired in somatotrophs of hypothyroid rats, whose cytoskeleton is disarranged. This study investigated the: eEF1A and GH mRNA binding to cytoskeleton plus GH mRNA translation rate and GH secretion, in sham-operated and thyroidectomized rats treated with T3 or saline, and killed 30 min thereafter. Thyroidectomy reduced: (a) pituitary F-actin content, and eEF1A plus GH mRNA binding to it; (b) GH mRNA recruitment to polysome; and (c) liver IGF-1 mRNA expression, indicating that GH mRNA stability and translation rate, as well as GH secretion were impaired. T3 acutely reversed all these changes, which points toward a nongenomic action of T3 on cytoskeleton rearrangement, which might contribute to the increase on GH mRNA translation rate and GH secretion. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

The impact of exchange-rate and trade policy on export performance in the 1980s

Includes bibliography

Identification of predominant economic agents and asymmetric regulation

In recognition of the telecommunications industry’s increasing importance for the growth and competitiveness of Latin American countries, this edition of the FAL Bulletin is based on the presentation given by Mr. Patricio Rozas of the Infrastructure Services Unit of the Economic Commission for Latin America and the Caribbean (ECLAC), at the International Forum on New Telecommunications and Broadcasting Models, organized by the Senate of the Republic of Mexico and held in Mexico City between 28 and 30 October 2013.

Endocrine and paracrine regulation of zebrafish spermatogenesis: the Sertoli cell perspective

Spermatogonial stem cells (SSCs) either self-renew or differentiate into spermatogonia that further develop into spermatozoa. Self-renewal occurs when residing in a specific micro-environment (niche) while displacement from the niche would tip the signalling balance towards differentiation. Considering the cystic type of spermatogenesis in fish, the SSC candidates are single type A undifferentiated (A(und)) spermatogonia, enveloped by mostly one niche-forming Sertoli cell. When going through a self-renewal cell cycle, the resulting new single type Aund spermatogonium would have to recruit another Sertoli cell to expand the niche space, while a differentiating germ cell cyle would result in a pair of spermatogonia that remain in contact with their cyst-forming Sertoli cells. In zebrafish, thyroid hormone stimulates the proliferation of Sertoli cells and of type Aund spermatogonia, involving Igf3, a new member of the Igf family. In cystic spermatogenesis, type Aund spermatogonia usually do not leave the niche, so that supposedly the signalling in the niche changes when switching from self-renewal to differentiation. and rzAmh inhibited differentiation of type A(und) spermatogonia as well as Fsh-stimulated steroidogenesis. Thus, for Fsh to efficiently stimulate testis functions, Amh bioactivity should be dampened. We also discovered that Fsh increased Sertoli cell Igf3 gene and protein expression; rzIgf3 stimulated spermatogonial proliferation and Fsh-stimulated spermatogenesis was significantly impaired by inhibiting Igf receptor signaling. We propose that in zebrafish, Fsh is the major regulator of testis functions and, supported by other endocrine systems (e.g. thyroid hormone), regulates Leydig cell steroidogenesis as well as Sertoli cell number and growth factor production to promote spermatogenesis.

Epigenetic and oncogenic regulation of SLC16A7 (MCT2) results in protein over-expression, impacting on signalling and cellular phenotypes in prostate cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Submandibular glands and the regulation of gastric proliferation and TGFα distribution during rat postnatal development

Rodent gastric mucosa grows and differentiates during suckling-weaning transition. Among the molecules in rat milk, EGF and TGFβ are important peptides in the control of cell proliferation, and together with TGFα, they are also produced by submandibular glands. We aimed to determine the effect of saliva and milk on epithelial cell proliferation in the stomach of rat pups. We also examined the distribution of TGFα in the gastric mucosa after sialoadenectomy (SIALO) and fasting in order to determine whether this growth factor is affected by the deprivation of molecules derived from saliva and milk. SIALO was performed at 14 days and fasting was induced 3 days later. Cell proliferation was evaluated through metaphasic index and TGFα was detected by immunohistochemistry. We observed that whereas SIALO did not alter cell division, since the metaphasic index (MI) was unchanged, fasting stimulated cell proliferation (P < 0.05). After SIALO and fasting, MI was reduced when compared to the fasted group (P < 0.05). We found that TGFα is distributed along gastric gland and SIALO did not interfere in the localization and number of immunolabeled cells, but fasting increased their density when compared to the control (P < 0.05). The association of SIALO and fasting reduced TGFα immunostaining (P < 0.05). Therefore, during fasting, high MI was parallel to increased TGFα in gastric epithelium, but interestingly, this effect was found only in the presence of submandibular glands. We suggest that during suckling, peptides derived from saliva and milk are important to regulate gastric growth.

Ingestion rate and egg production of copepods collected in the upper 20m in the eastern Mediterranean Sea in April 2008 during SES_GR2

The ingestion on ciliates and phytoplankton dataset is based on samples taken during October 2008 in Northern Aegean Sea, the area influenced by the Black Sea water outflow. A Lagrangian experiment was established and copepod ingestion was estimated from experiments performed at stations according to the different positions of drifters during the cruise. Copepods for the experiments were obtained with slow non-quantitative tows from the upper 20 m layer of the water column using 200 µm mesh size nets fitted with a large non-filtering cod end. For the grazing experiments we used the following copepod species: Clausocalanus furcatus, and Temoraa stylifera according to the relevant reference (Bamstedt et al. 2000). Copepod clearance rates on ciliates were calculated according to Frost equations (Frost 1972). Ingestion rates were calculated by multiplying clearance rates by the initial standing stocks (Bamstedt et al. 2000). The egg production dataset is based on samples taken during October 2008 in Northern Aegean Sea, the area influenced by the Black Sea water outflow. A Lagrangian experiment was established and copepod egg production was estimated from experiments performed at stations according to the different positions of drifters during the cruise. Egg production rates of the dominant calanoid copepods were determined by incubation of fertilised females (eggs female/day) collected in the 0-20m layer. Copepod egg production was measured for the copepods Clausocalanus furcatus, Temora stylifera. On board experiments for the estimation of copepod egg production were taken place. For the estimation of copepod production (mgC/m**2/day), lengths (copepods and eggs) were converted to body carbon (Hopcroft et al., 1998) and production was estimated from biomass and weight-specific egg production rates, by assuming that those rates are representative for juvenile specific growth rates (Berggreen et al., 1988).

Ingestion rate and egg production of copepods collected in the Turkish Strait during Bilim 2 cruise in April 2008

The copepod Ingestion on ciliates, phytoplankton and the copepod production dataset is based on samples taken during April 2008 in Dardanelles Straits, Marmara Sea and Bosporus Straits at the third priority stations. These experiments were set up according to DoW of Sesame project. Copepods for the experiments were obtained with slow non-quantitative tows from the upper 50 m layer of the water column using 200 µm mesh size nets fitted with a large non-filtering cod end. For the grazing experiments we used the following copepod species: Centropages typicus and Acartia clausi according to the relevant reference (Bamstedt et al. 2000). Copepod clearance rates on ciliates were calculated according to Frost equations (Frost 1972). Ingestion rates were calculated by multiplying clearance rates by the initial standing stocks (Bamstedt et al. 2000). Egg production rates of the dominant calanoid copepods were determined by incubation of fertilised females (eggs/female/day) collected in the 0-20m layer. Copepod egg production was measured for the copepods Centropages typicus and Acartia clausi. On board experiments for the estimation of copepod egg production were taken place. For the estimation of copepod production (mg/m**2/day), lengths (copepods and eggs) were converted to body carbon (Hopcroft et al., 1998) and production was estimated from biomass and weight-specific egg production rates, by assuming that those rates are representative for juvenile specific growth rates (Berggreen et al., 1988).

(Fig. 3) Sepia officinalis standard metobolic rate and seawater pH (NBS) during experiments, 2008

Ocean acidification and associated changes in seawater carbonate chemistry negatively influence calcification processes and depress metabolism in many calcifying marine invertebrates. We present data on the cephalopod mollusc Sepia officinalis, an invertebrate that is capable of not only maintaining calcification, but also growth rates and metabolism when exposed to elevated partial pressures of carbon dioxide (pCO2). During a 6 wk period, juvenile S. officinalis maintained calcification under ~4000 and ~6000 ppm CO2, and grew at the same rate with the same gross growth efficiency as did control animals. They gained approximately 4% body mass daily and increased the mass of their calcified cuttlebone by over 500%. We conclude that active cephalopods possess a certain level of pre-adaptation to long-term increments in carbon dioxide levels. Our general understanding of the mechanistic processes that limit calcification must improve before we can begin to predict what effects future ocean acidification will have on calcifying marine invertebrates.

Stable isotope record, opal accumulation rate and geochemistry of middle Miocene sediments of IODP Site 321-U1338

During the middle Miocene, Earth's climate transitioned from a relatively warm phase (Miocene climatic optimum) into a colder mode with re-establishment of permanent ice sheets on Antarctica, thus marking a fundamental step in Cenozoic cooling. Carbon sequestration and atmospheric CO2 drawdown through increased terrestrial and/or marine productivity have been proposed as the main drivers of this fundamental transition. We integrate high-resolution (1-3 k.y.) benthic stable isotope data with XRF-scanner derived biogenic silica and carbonate accumulation estimates in an exceptionally well-preserved sedimentary archive, recovered at Integrated Ocean Drilling Program Site U1338, to reconstruct eastern equatorial Pacific productivity variations and to investigate temporal linkages between high- and low-latitude climate change over the interval 16-13 Ma. Our records show that the climatic optimum (16.8-14.7 Ma) was characterized by high amplitude climate variations, marked by intense perturbations of the carbon cycle. Episodes of peak warmth at (southern hemisphere) insolation maxima coincided with transient shoaling of the carbonate compensation depth and enhanced carbonate dissolution in the deep ocean. A switch to obliquity-paced climate variability after 14.7 Ma concurred with a general improvement in carbonate preservation and the onset of stepwise global cooling, culminating with extensive ice growth over Antarctica at ~13.8 Ma. We find that two massive increases in opal accumulation at ~14.0 and ~13.8 Ma occurred just before and during the final and most prominent cooling step, supporting the hypothesis that enhanced siliceous productivity in the eastern equatorial Pacific contributed to CO2 drawdown.

Ingestion rate and egg production of copepods collected in the upper 20m in the eastern Mediterranean Sea in March and April 2008 during SES_GR1

The ingestion on ciliates and phytoplankton dataset is based on samples taken during April 2008 in Northern Aegean Sea, the area influenced by the Black Sea water outflow. A Lagrangian experiment was established and copepod ingestion was estimated from experiments performed at stations according to the different positions of drifters during the cruise. Copepods for the experiments were obtained with slow non-quantitative tows from the upper 20 m layer of the water column using 200 µm mesh size nets fitted with a large non-filtering cod end. For the grazing experiments we used the following copepod species: Centropages typicus and Calanus helgolandicus according to the relevant reference (Bamstedt et al. 2000). Copepod clearance rates on ciliates were calculated according to Frost equations (Frost 1972). Ingestion rates were calculated by multiplying clearance rates by the initial standing stocks (Bamstedt et al. 2000). The egg production dataset is based on samples taken during April 2008 in Northern Aegean Sea, the area influenced by the Black Sea water outflow. A Lagrangian experiment was established and copepod egg production was estimated from experiments performed at stations according to the different positions of drifters during the cruise. Egg production rates of the dominant calanoid copepods were determined by incubation of fertilised females (eggs female/day) collected in the 0-20m layer. Copepod egg production was measured for the copepods Centropages typicus, Calanus helgolandicus. On board experiments for the estimation of copepod egg production were taken place. For the estimation of copepod production (mgC/ m**2 /day), lengths (copepods and eggs) were converted to body carbon (Hopcroft et al., 1998) and production was estimated from biomass and weight-specific egg production rates, by assuming that those rates are representative for juvenile specific growth rates (Berggreen et al., 1988).

Ingestion rate and egg production of copepods collected in the upper 20m in the eastern Mediterranean Sea in Oktober 2008

This dataset based on samples taken during October 2008 in Dardanelles Straits, Marmara Sea and Bosporus Straits at the third priority stations. Copepods for the experiments were obtained with slow non-quantitative tows from the upper 50 m layer of the water column using 200 µm mesh size nets fitted with a large non-filtering cod end. For the grazing experiments we used the following copepod species: Oithona spp., Clausocalanus furcatus, Acartia clausi and Oncaea spp. and in one cladoceran species Penilia avirostris according to the relevant reference (Bamstedt et al. 2000). Copepod clearance rates on ciliates were calculated according to Frost equations (Frost 1972). Ingestion rates were calculated by multiplying clearance rates by the initial standing stocks (Bamstedt et al. 2000). Egg production rates of the dominant calanoid copepods were determined by incubation of fertilised females (eggs/female/day) collected in the 0-20m layer. Copepod egg production was measured for the copepods Clausocalanus furcatus, Paracalanus parvus,Acaria clausi. On board experiments for the estimation of copepod egg production were taken place. For the estimation of copepod production (mg/m**2/day), lengths (copepods and eggs) were converted to body carbon (Hopcroft et al., 1998) and production was estimated from biomass and weight-specific egg production rates, by assuming that those rates are representative for juvenile specific growth rates (Berggreen et al., 1988).