Anatomical and Physiological Plasticity in Leymus chinensis (Poaceae) along Large-Scale Longitudinal Gradient in Northeast China

Although it has been widely accepted that global changes will pose the most important constrains to plant survival and distribution, our knowledge of the adaptive mechanism for plant with large-scale environmental changes (e.g. drought and high temperature) remains limited.An experiment was conducted to examine anatomical and physiological plasticity in Leymus chinensis along a large-scale geographical gradient from 115° to 124°E in northeast China. Ten sites selected for plant sampling at the gradient have approximately theoretical radiation, but differ in precipitation and elevation. The significantly increasing in leaf thickness, leaf mass per area, vessel and vascular diameters, and decreasing in stoma density and stoma index exhibited more obvious xerophil-liked traits for the species from the moist meadow grassland sites in contrast to that from the dry steppe and desert sites. Significant increase in proline and soluble sugar accumulation, K(+)/Na(+) for the species with the increasing of stresses along the gradient showed that osmotic adjustment was enhanced.Obvious xerophytic anatomical traits and stronger osmotic adjustment in stress conditions suggested that the plants have much more anatomical and physiological flexibilities than those in non-stress habitats along the large-scale gradient

Natural Variation in Arabidopsis thaliana as a Tool for Highlighting Differential Drought Responses

To test whether natural variation in Arabidopsis could be used to dissect out the genetic basis of responses to drought stress, we characterised a number of accessions. Most of the accessions belong to a core collection that was shown to maximise the genetic diversity captured for a given number of individual accessions in Arabidopsis thaliana. We measured total leaf area (TLA), Electrolyte Leakage (EL), Relative Water Content (RWC), and Cut Rosette Water Loss (CRWL) in control and mild water deficit conditions. A Principal Component Analysis revealed which traits explain most of the variation and showed that some accessions behave differently compared to the others in drought conditions, these included Ita-0, Cvi-0 and Shahdara. This study relied on genetic variation found naturally within the species, in which populations are assumed to be adapted to their environment. Overall, Arabidopsis thaliana showed interesting phenotypic variations in response to mild water deficit that can be exploited to identify genes and alleles important for this complex trait

Postępowanie w chorobach tarczycy u kobiet w ciąży

The management of thyroid disorders during pregnancy is one of the most frequently disputed problems in modern endocrinology. It is widely known that thyroid dysfunction may result in subfertility, and, if inadequately treated during pregnancy, may cause obstetrical complications and influence fetal development. The 2007 Endocrine Society Practice Guideline endorsed with the participation of the Latino America Thyroid Association, the American Thyroid Association, the Asia and Oceania Thyroid Association and the European Thyroid Association, greatly contributed towards uniformity of the management of thyroid disorders during pregnancy and postpartum. Despite the tremendous progress in knowledge on the mutual influence of pregnancy and thyroid in health and disease, there are still important areas of uncertainty. There have been at least a few important studies published in the last 3 years, which influenced the thyroidal care of the expecting mother. It should also be remembered that guidelines may not always be universally applied in all populations with different ethnical, socio-economical, nutritional (including iodine intake) background or exposed to different iodine prophylaxis models. The Task Force for development of guidelines for thyroid dysfunction management in pregnant women was established in 2008. The expert group has recognized the following tasks: development of the coherent model of the management of thyroid dysfunction in pregnant women, identification of the group of women at risk of thyroid dysfunction, who may require endocrine care in the preconception period, during pregnancy and postpartum – that is in other words, the development of Polish recommendations for targeted thyroid disorder case finding during pregnancy, and the development of Polish trimester-specific reference values of thyroid hormones. Comprehensive Polish guidelines developed by the Task Force are to systematize the management of the thyroid disorders in pregnant women in Poland. (Pol J Endocrinol 2011; 62 (4): 362–381)Jednym z aktualnie szeroko dyskutowanych problemów współczesnej endokrynologii jest opieka tyreologiczna nad kobietą ciężarną. Powszechnie wiadomo, że dysfunkcja tarczycy może być przyczyną zaburzeń płodności, a nieleczona prawidłowo w czasie ciąży zwiększa ryzyko powikłań położniczych oraz ma wpływ na rozwój płodu. Opublikowane w 2007 roku wytyczne Towarzystwa Endokrynologicznego (Endocrine Society), opracowane przy współudziale Towarzystwa Tyreologicznego Ameryki Łacińskiej (LATS), Towarzystwa Tyreologicznego Azji i Oceanii (AOTA), Amerykańskiego Towarzystwa Tyreologicznego (ATA) oraz Europejskiego Towarzystwa Tyreologicznego (ETA), w dużym stopniu usystematyzowały zasady postępowania w chorobach tarczycy w czasie ciąży i w okresie poporodowym. Pomimo ogromnego postępu wiedzy na temat wzajemnego wpływu ciąży i funkcji gruczołu tarczowego w zdrowiu i chorobie, jaki osiągnięto w ciągu ostatnich kilkunastu lat, nadal pewne obszary wymagają dalszych badań. W ciągu 3 lat, które minęły od publikacji wytycznych, przybyło danych, które wpłynęły na niektóre zasady prowadzenia ciężarnej z chorobą tarczycy. Wytyczne nie zawsze mają charakter uniwersalny i nie mogą być w prosty sposób transponowane na społeczeństwa zróżnicowane etnicznie i ekonomicznie, o odmiennych zwyczajach dietetycznych, w tym w spożyciu nośników jodu, oraz stosujące odmienne modele profilaktyki jodowej. W 2008 roku powołano Zespół Ekspertów do spraw Opieki Tyreologicznej w Ciąży. Za cele prac Zespołu przyjęto: opracowanie modelu opieki nad ciężarną z zaburzeniami funkcji tarczycy, określenie grupy kobiet z ryzykiem zaburzeń funkcji tarczycy wymagających oceny tyreologicznej podczas planowania ciąży, w trakcie jej trwania oraz w okresie poporodowym — czyli przygotowanie polskich wskazań do badań przesiewowych oraz ustalenie wartości referencyjnych stężeń hormonów tarczycy w poszczególnych trymestrach ciąży. Opracowane przez Zespół wytyczne systematyzują zasady opieki tyreologicznej nad kobietą ciężarną w Polsce. (Endokrynol Pol 2011; 62 (4): 362–381

Dislexia e ensino-aprendizagem de língua portuguesa : um estudo de caso

Monografia (graduação)—Universidade de Brasília, Instituto de Letras, 2013.Esta pesquisa trata da dislexia e do ensino-aprendizagem de Língua Portuguesa para disléxicos, com base em um estudo de caso com estudante disléxico da rede pública de ensino do Plano Piloto. Dentre as questões abordadas, estão as definições da dislexia, seus tipos e possíveis tratamentos, além da discussão do espaço que tal distúrbio de aprendizagem tem na educação, a sugestão de inclusão da dislexia na Educação Especial e, consequentemente, nas salas de recursos e a adequação da metodologia de ensino, baseada na exploração dos gêneros textuais e dos multiletramentos, dentro da perspectiva Sociointeracionista de Vygotsky e da proposta de professor libertador, de Paulo Freire

A comparison of the effects of drought on proline accumulation and peroxidases activity in leaves of Festuca rubra L. and Lolium perenne L.

The effect of soil drought on leaf water content, proline content, and the activity of guaiacol (GuPX) and ascorbate (APX) peroxidases as well as the level of lipid peroxidation were investigated in leaves of drought resistant red fescue (Festuca rubra) and drought sensitive perennial ryegrass (Lolium perenne). Plants were grown under glasshouse conditions in soil pot culture. 26 day-old grasses were exposed to drought by withholding irrigation for 18 days. Water content in leaves of perennial ryegrass decreased more than in red fescue throughout the experimental period. On the other hand, proline content (PC) was higher in red fescue. The activity of APX and GuPX increased in leaves of red fescue, while it did not change in perennial ryegrass. Our data demonstrate that both red fescue and perennial ryegrass were able to survive applied drought, as shown by a lack of stress-induced lipid peroxidation and hence no evidence of oxidative damage. We speculate, that the observed drought stress tolerance at cellular level was associated with the ability to accumulate proline, and to maintain high activity of APX and GuPX, resulting in protection against oxidative damage and lipid peroxidation. It seems that this mechanism works better in red fescue

Seasonal patterns of free proline and carbohydrate levels in cherry laurel (Prunus laurocerasus) and ivy (Hederea helix) leaves and resistance to freezing and water deficit

Seasonal changes in the levels of water-soluble carbohydrates, free proline and tolerance to freezing and water deficit were studied in leaves of cherry laurel (Prunus laurocerasus) and ivy (Hedera helix). Frost and water deficit tolerance was estimated based on the measurement of electrical conductivity of aqueous media containing leaf discs that were previously treated with frost (–7°C) or polyethylene glycol solution (PEG 600), respectively. Carbohydrate content in leaves of examined species changed differently throughout the measurement period. In laurel leaves the highest carbohydrate level was found in February, while it was lowest in June. In contrast, in ivy leaves the highest carbohydrate content was recorded during summer (June, July), while the lowest in February. However, a lack of correlation between soluble carbohydrate level and membrane injury index was shown in this study. Free proline content in leaves of investigated species was the highest in early spring, i.e. April. The lowest level of free proline in laurel leaves was found in July, September and October, but in ivy from July to February. A negative correlation between proline content and membrane injury index observed in frost and PEG treated leaves of both species suggest that this amino acid may have resulted on membrane protection

Kumulatywny wpływ ozonu na aktywność enzymów antyoksydacyjnych u tytoniu rosnącego na dwóch stanowiskach ekspozycyjnych

Tropospheric ozone is a harmful air pollutant which may cause oxidative stress in plant cells, leading to biochemical and physiological changes and yield reduction. The aim of the study was to examine the cumulative effect of long-term ozone stress on the activity of antioxidative enzymes in leaves of ozone sensitive and resistant tobacco cultivar growing at the sites of various ozone concentrations. The one-month experiment was conducted in the 2009, 2010 and 2011 growing seasons with different meteorological conditions and ozone concentrations. The activity of SOD, APX and GuPX was measured four times at weekly intervals. The highest tropospheric ozone concentration was recorded in 2010 along with high level of solar radiation and temperature. The enhanced ozone level caused the increase in the activity of all examined enzymes. However, at more elevated ozone level the activity of all enzymes was higher in sensitive (Bel W3) than resistant (Bel B) tobacco cultivar. On the other hand, at lower ozone level the activity of examined enzymes was rather similar in both cultivars or even higher in ozone-resistant one, which was especially valid for SOD. A positive correlation between the activity of all enzymes and ozone concentration was shown in both cultivars. The presented results show that meteorological conditions modify tropospheric ozone concentration and real plant response to this environmental pollutant. It is highly important to interpret week-by-week plant response and environmental conditions bearing in mind the cumulative ozone effect resulting from previous weeks conditions.Zwiększone stężenie ozon troposferycznego w powietrzu jest szkodliwe dla roślin, gdyż przyczynia się do powstania stresu oksydacyjnego prowadzącego do zmian biochemiczno-fizjologicznych oraz redukcji plonów. Celem pracy było zbadanie wpływu długotrwałego stresu ozonowego na aktywność enzymów antyoksydacyjnych w liściach wrażliwej oraz odpornej na ozon odmiany tytoniu rosnących na stanowiskach ekspozycyjnych różniących się stężeniem tego zanieczyszczenia. Przeprowadzono trzy trwające jeden miesiąc doświadczenia w latach 2009, 2010 i 2011 charakteryzujących się różnymi warunkami meteorologicznymi oraz różnym stężeniem ozonu. Aktywność SOD, APX oraz GuPX oznaczano czterokrotnie (w odstępach tygodniowych) w czasie ekspozycji roślin. Najwyższe stężenie ozonu stwierdzono w roku 2010, kiedy odnotowano również wysoki poziom promieniowania słonecznego oraz temperatury powietrza. Zwiększone stężenie ozonu przyczyniło się do wzrostu aktywności badanych enzymów. Większą aktywność enzymów w warunkach podwyższonego stężenia ozonu stwierdzono u wrażliwej (Bel W3) niż odpornej (Bel B) odmiany tytoniu. Przy niższym stężeniu ozonu, aktywność badanych enzymów była zbliżona u obu odmian, lub nawet wyższa u odmiany odpornej, co było szczególnie widoczne w przypadku SOD. U obu odmian stwierdzono pozytywną korelacje pomiędzy aktywnością badanych enzymów oraz stężeniem ozonu. Uzyskane wyniki wskazują, że warunki atmosferyczne wpływają na stężenie ozonu troposferycznego, co z kolei wpływa na rzeczywistą odpowiedź rośliny na to gazowe zanieczyszczenie powietrza. Niezwykle ważne jest, aby uzyskane dane dotyczące odpowiedzi roślin na zanieczyszczenie powietrza ozonem interpretować z uwzględnieniem czasowych zależności, w szczególności efektu kumulowania się wpływu ozonu w poprzedzającym przedziale czasowym