Some don't like it hot: microhabitat-dependent thermal and water stresses in a trailing edge population

The distributional limits of species in response to environmental change are usually studied at large temporal and/or geographical scales. However, organismal scale habitat variation can be overlooked when investigating large-scale averages of key factors such as temperature. We examine how microhabitat thermal conditions relate to physiological limits, which may contribute to recent range shifts in an intertidal alga. We defined the onset and maximum temperatures of the heat-shock response (HSR) for a southern edge population of Fucus vesiculosus, which has subsequently become extinct. The physiological threshold for resilience (assayed using chlorophyll fluorescence) coincided with declining HSR, determined from the temperature-dependent induction of seven heat-shock protein transcripts. In intertidal habitats, temperature affects physiology directly by controlling body temperature and indirectly through evaporative water loss. We investigated the relationship between the thermal environment and in situ molecular HSR at microhabitat scales. Over cm to m scales, four distinct microhabitats were defined in algal patches (canopy surface, patch edge, subcanopy, submerged channels), revealing distinct thermal and water stress environments during low-tide emersion. The in situ HSR agreed with estimated tissue temperatures in all but one microhabitat. Remarkably, in the most thermally extreme microhabitat (canopy surface), the HSR was essentially absent in desiccated tissue, providing a potential escape from the cellular metabolic costs of thermal stress. Meteorological records, microenvironmental thermal profiles and HSR data indicate that the maximum HSR is approached or exceeded in hydrated tissue during daytime low tides for much of the year. Furthermore, present-day summer seawater temperatures are sufficient to induce HSR during high-tide immersion, preventing recovery and resulting in continuous HSR during daytime low-tide cycles over the entire summer. HSR in the field matched microhabitat temperatures more closely than local seawater or atmospheric data, suggesting that the impacts of climatic change are best understood at the microhabitat scale, particularly in intertidal areas.FCT - Portuguese Science Foundation [POCTI/MAR/61105/2004, EXCL/AAG-GLO/0661/2012, SFRH/BPD/63/03/2009, SFRH/BD/74436/2010]info:eu-repo/semantics/publishedVersio

Mosquito Larvicidal Constituents from Lantana Viburnoides SP Viburnoides Var Kisi (A. rich) Verdc (Verbenaceae).

\ud \ud Lantana viburnoides sp viburnoides var kisi is used in Tanzania ethnobotanically to repel mosquitoes as well as in traditional medicine for stomach ache relief. Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks were carried out in order to identify the bioactive components for controlling Anopheles gambiae s.s. mosquito larvae. Twenty late III or early IV instar larvae of An. gambiae s.s. were exposed to various concentrations of the plant extracts, fractions, blends and pure compounds, and were assayed in the laboratory by using the protocol of WHO 1996. Mean mortalities were compared using Dunnett's test (p < 0.05) and lethal concentration calculated by Lackfit Inversel of the SAS programme. The crude extract (LC50 = 7.70 ppm in 72 h) and fractions exhibited different level of mosquito larvicidal activity with subtraction of some fractions resulting in activity enhancement. The active fractions contained furanonaphthaquinones regio-isomers (LC50 = 5.48-5.70 ppm in 72 h) and the lantadene triterpenoid camaric acid (LC50 = 6.19 ppm in 72 h) as active principles while the lupane triterpenoid betulinic acid (LC50 < 10 ppm in 72 h) was obtained from the least active fraction. Crude extracts and some fractions had higher or comparable larvicidal activity to the pure compounds. These results demonstrate that L. viburnoides sp viburnoides var kisi extracts may serve as larvicides for managing various mosquito habitats even in their semi-purified form. The isolated compounds can be used as distinct markers in the active extracts or plant materials belonging to the genus Lantana

An Activity-Based Nanosensor for Traumatic Brain Injury.

Currently, traumatic brain injury (TBI) is detected by medical imaging; however, medical imaging requires expensive capital equipment, is time- and resource-intensive, and is poor at predicting patient prognosis. To date, direct measurement of elevated protease activity has yet to be utilized to detect TBI. In this work, we engineered an activity-based nanosensor for TBI (TBI-ABN) that responds to increased protease activity initiated after brain injury. We establish that a calcium-sensitive protease, calpain-1, is active in the injured brain hours within injury. We then optimize the molecular weight of a nanoscale polymeric carrier to infiltrate into the injured brain tissue with minimal renal filtration. A calpain-1 substrate that generates a fluorescent signal upon cleavage was attached to this nanoscale polymeric carrier to generate an engineered TBI-ABN. When applied intravenously to a mouse model of TBI, our engineered sensor is observed to locally activate in the injured brain tissue. This TBI-ABN is the first demonstration of a sensor that responds to protease activity to detect TBI

Evolution of the Fucaceae (Phaeophyceae) inferred from nrDNA-ITS

Sequences of the internal transcribed spacer region (ITS-1, 5.8S, and ITS-2) of nuclear ribosomal DNA were obtained from 16 species representing all six genera of Fucaceae (Ascophyllum, Fucus, Hesperophycus, Pelvetia, Pelvetiopsis, and Xiphophora) plus one outgroup (Hormosira). Parsimony analysis indicated that the family Fucaceae is monophyletic and that the northern hemisphere taxa are highly divergent from the only southern hemisphere genus, Xiphophora. The genus Pelvetia is not monophyletic because the European P. canaliculata is more closely related to Fucus, Hesperophycus, and Pelvetiopsis than to other Pelvetia species. We establish Silvetia, gen. nov. and transfer the 3 Pacific species of Pelvetia to the new genus. Fucus is monophyletic and not ancestral in the Fucaceae. The ITS sequences identified two strongly supported lineages within Fucus, one with F. serratus sister to the clade containing F. gardneri, F. distichus, and F. evanescens and a second including F. vesiculosus, F. spiralis, F. ceranoides, and F. virsoides. The ITS was not useful for resolving relationships within each of these clusters and between populations of F. vesiculosus. Within-individual variation in ITS sequences is high in Fucus, a derived genus, compared to Ascophyllum, a more ancestral genus. Mapping of the two characters that form the basis of Powell’s model for speciation in the Fucaceae showed that 1) number of eggs per oogonium has not followed a gradual reduction and that 2) monoecy/dioecy has changed several times during evolution of this family

Het labyrint in de letterkunde: Van de Barok tot het Postmodernisme

The labyrinth in literature: From Baroque to Postmodernism The labyrinth has proved to be an essential symbol of postmodernist literature and the philosophy of our time. This symbol has apparently had the power to bridge the centuries between Ancient Greece and the year 2000. In reality the labyrinth as a geometrical figure has acquired various meanings in the course of time. The history of the labyrinth as symbol shows that the constant elements are as essential as the changes in meaning from the Middle Ages until the present day. Two of the new symbolic elements that accompany the labyrinth on its way through various cultural periods are the garden and the path of life. During the Baroque the labyrinth, for example, represented the synthesis of garden, path and maze. At the end of the twentieth century the labyrinth once more becomes a dominant and significant structure. The labyrinth reflects the inability and perhaps impossibility to find the key to the centre of the world and to discover the truth behind the words we use. On the other hand, the labyrinth suggests that the search for meaning and truth is an aim in itself or even that this search can lead to new forms of wisdom. The labyrinth therefore is an ambivalent and fascinating symbol of our time. Dedalus and Ariadne, however, have not yet brought the salvation we are waiting for

Diversity Of Types And Abundance Of Algae, In Meras Waters Of North Sulawesi, Photosynthesis Pigments And Cell Structure

Research on the diversity of algae types and their abundance in Meras waters has been carried out using structured line transect sampling and quadrant placement methods. The result is a diversity of algae types with a Shannon index (H') above 1.75. This shows that the diversity of algae types is moderate where water conditions are still good enough for algae growth. This is reinforced by the results of analysis of the structure of algal cells using TEM which found the presence of Floridian starch as evidence of the photosynthesis process taking place in these waters. When algae to grow and develop will carry out the process of photosynthesis. There were 9 species of algae found spread across 3 classes, namely 3 species of Chlorophyceae, 4 species of Phaeophyceae, and 3 species of Rhodophyceae. The results of the analysis of species abundance in these waters show that the algae species Gracilaria edulis is the most abundant, namely 7.6 individuals/m2, while the relative abundance is 0.28. The results of the analysis of photosynthetic pigments in the algae Gracilaria edulis were chlorophyll a, namely 359.335 µg, chlorophyll d 47.385 µg, and 1627.75 µg of carotene pigment. This algae pigment can be used as a raw material in the food (nutrification) and pharmaceutical industries. Keywords: Diversity of algae types, pigments, and cell structure Abstrak Penelitian Keanekaragaman jenis alga dan kelimpahannya  di perairan Meras telah dilakukan  dengan metode  pengambilan sampel line transek dan peletakan kuadran secara terstruktur. Hasilnya adalah keanekaragaman jenis alga dengan index Shannon (H’) berada di atas 1,75 Hal ini menunjukkan bahwa keanekaragaman jenis alga sedang dimana kondisi perairan masih cukup baik untuk pertumbuhan alga. Hal ini diperkuat dengan hasil analisis struktur sel alga menggunakan TEM ditemukan adanya  floridean starch bukti adanya berlangsung proses fotosintesis di perairan tersebut. Dimana alga untuk tumbuh dan berkembang akan melakukan  proses fotosintesis. Spesies alga yang ditemukan sebanyak 9 spesies yang tersebar dalam 3 kelas yaitu Chlorophyceae 3 spesies, Phaeophyceae  4 spesies dan 3 spesies Rhodophyceae. Hasil analisis kelimpahan spesies di perairan tersebut  menunjukkan bahwa spesies alga Gracilaria edulis paling melimpah yaitu 7,6 individu/m2 sedangkan kelimpahan relatifnya adalah 0,28. Hasil analisis pigmen fotosintesis  pada alga Gracilaria edulis adalah klorofil a yaitu 359,335 µg,  klorofil d 47,385 µg dan 1627,75 µg pigmen karoten. Pigmen alga ini dapat dimanfaatkan sebagai bahan baku dalam industri makanan (nutrifikasi) dan farmasetika. Kata kunci : Keanekaragaman jenis alga, pigmen, dan struktur sel