Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 92
Filter
Add more filters

Publication year range
1.
Glob Chang Biol ; 30(1): e16991, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37905464

ABSTRACT

Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a "middle of the road" scenario (SSP2-4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26-43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present-day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from -20 to -191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.


Subject(s)
Turtles , Animals , Turtles/physiology , Temperature , Climate Change , Reproduction , Sex Ratio
3.
Phys Rev Lett ; 117(15): 156601, 2016 Oct 07.
Article in English | MEDLINE | ID: mdl-27768332

ABSTRACT

We combine numerical diagonalization with semianalytical calculations to prove the existence of the intermediate nonergodic but delocalized phase in the Anderson model on disordered hierarchical lattices. We suggest a new generalized population dynamics that is able to detect the violation of ergodicity of the delocalized states within the Abou-Chakra, Anderson, and Thouless recursive scheme. This result is supplemented by statistics of random wave functions extracted from exact diagonalization of the Anderson model on ensemble of disordered random regular graphs (RRG) of N sites with the connectivity K=2. By extrapolation of the results of both approaches to N→∞ we obtain the fractal dimensions D_{1}(W) and D_{2}(W) as well as the population dynamics exponent D(W) with the accuracy sufficient to claim that they are nontrivial in the broad interval of disorder strength W_{E}10^{5} reveals a singularity in D_{1,2}(W) dependencies which provides clear evidence for the first order transition between the two delocalized phases on RRG at W_{E}≈10.0. We discuss the implications of these results for quantum and classical nonintegrable and many-body systems.

4.
J Fish Biol ; 88(6): 2130-43, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27161769

ABSTRACT

The expression and digestive activity of pike silverside Chirostoma estor endogenous chitinases were analysed in samples from four life stages: whole eggs; larvae; juvenile intestine and hepatopancreas and adult intestine and hepatopancreas. A chitinase cDNA was cloned and partially sequenced (GenBank accession number: FJ785521). It was highly homologous to non-acidic chitinase sequences from other fish species, suggesting that it is a chitotriosidase. Quantitative PCR showed that this chitinase was expressed throughout the life span of C. estor, with maximum expression in the hepatopancreas of juveniles. Chitotriosidase and chitobiosidase activities were found at all life stages, along with a very high level of N-acetyl glucosaminidase (NAGase). The chitotriosidase activity could be encoded by the cloned complementary (c)DNA, although additional chitinase genes may be present. The chitotriosidase activity appeared to be transcriptionally regulated only at the juvenile stage. The expression and activity of chitinases tended to increase from the early to juvenile stages, suggesting that these variables are stimulated by chitin-rich live food. Nevertheless, the feeding of juvenile and adult fish with both live food and a balanced commercial diet seemed to provoke significant reductions in pancreatic NAGase secretion and/or synthesis in the gut. Moreover, all chitinase activities were lower in adults, probably reflecting a higher intake and use of the balanced diet. The observation of chitotriosidase and chitobiosidase activities together with a very high NAGase activity suggest the presence of a complete and compensatory chitinolytic chitinase system that enables this stomachless short-gut fish species to use chitin as an energy substrate. These novel findings suggest that dietary inclusions of chitin-rich ingredients or by-products might reduce the farming costs of C. estor without impairing performance.


Subject(s)
Chitin/metabolism , Chitinases/metabolism , Fishes/metabolism , Animals , Chitinases/chemistry , Chitinases/genetics , Cloning, Molecular , DNA, Complementary , Fishes/genetics , Gene Expression , Hexosaminidases/chemistry , Hexosaminidases/genetics , Hexosaminidases/metabolism , Intestinal Mucosa/metabolism , Larva/genetics , Larva/metabolism , Ovum/metabolism , Pancreas/metabolism
5.
Clin Exp Dermatol ; 40(3): 298-300, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25557471

ABSTRACT

Idiopathic facial aseptic granuloma (IFAG) is a condition that is commonly encountered in clinical practice, but is rarely reported. It appears in childhood and its pathogenesis is still unknown. It has a benign course with resolution within a few months without aggressive treatment. Microbiological tests are negative and histological findings are nonspecific. It is possible that this condition is part of the spectrum of granulomatous rosacea in childhood. We present two cases in which diagnosis of IFAG was established and resolved without sequelae following topical antibiotic treatment.


Subject(s)
Facial Dermatoses/pathology , Granuloma/pathology , Adolescent , Child , Diagnosis, Differential , Female , Humans , Male , Rosacea/pathology
6.
Reprod Domest Anim ; 50(1): 104-11, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25405800

ABSTRACT

Oviductal regions show particular histological characteristics and functions. Tubal pathologies and hypothyroidism are related to primary and secondary infertility. The impact of hypothyroidism on the histological characteristics of oviductal regions has been scarcely studied. Our aim was to analyse the histological characteristics of oviductal regions in control and hypothyroid rabbits. Hypothyroidism was induced by oral administration of methimazole (MMI) for 30 days. For both groups, serum concentrations of thyroid and gonadal hormones were determined. Sections of oviductal regions were stained with the Masson's trichrome technique to analyse both epithelial and smooth muscle layers. The percentage of proliferative epithelial cells (anti-Ki67) in diverse oviductal regions was also quantified. Data were compared with Student t-test, Mann-Whitney U-test, or Fischer's test. In comparison with the control group, the hypothyroid group showed: (i) a low concentration of T3 and T4, but a high level of TSH; (ii) similar values of serum estradiol, progesterone and testosterone; (iii) a large size of ciliated cells in the ampulla (AMP), isthmus (IST) and utero-tubal junction (UTJ); (iv) a large size of secretory cells in the IST region; (v) a low percentage of proliferative secretory cells in the fimbria-infundibulum (FIM-INF) region; and (vi) a similar thickness of the smooth muscle layer and the cross-sectional area in the AMP and IST regions. Modifications in the size of the oviductal epithelium in hypothyroid rabbits could be related to changes in the cell metabolism that may impact on the reproductive functions achieved by oviduct.


Subject(s)
Cell Size , Epithelial Cells/pathology , Fallopian Tubes/pathology , Hypothyroidism/pathology , Animals , Cell Proliferation , Female , Hypothyroidism/blood , Hypothyroidism/chemically induced , Methimazole , Muscle, Smooth/pathology , Rabbits , Thyrotropin/blood , Thyroxine/blood , Triiodothyronine/blood
7.
Actas Dermosifiliogr ; 106(10): 806-15, 2015 Dec.
Article in English, Spanish | MEDLINE | ID: mdl-26272626

ABSTRACT

BACKGROUND AND OBJECTIVE: In the latest edition of its cancer staging manual, the American Joint Committee on Cancer (AJCC) revised the criteria for staging squamous cell carcinoma (SCC) by introducing high-risk tumor features to define tumor stage (T) and help to identify tumors with a higher risk of metastasis. The aim of this study was to investigate the characteristics associated with SCC meeting the high-risk criteria defined by the AJCC for T2 lesions. PATIENTS AND METHOD: We performed a case-case observational study in which patients with SCC were included over a period of 18 months. We collected clinical, anthropometric, and tumor data, and analyzed these using PASW Statistics (SPSS) version 18. RESULTS: One-hundred eighteen patients, the majority of whom were men, were included. Mean age was 77 years. Over 70% of the tumors were located in the head region and a majority of tumors measured 2 cm or less. The prevalence of SCC T2 was 61.9%. The risk factors significantly associated with SCC T2 were an age of over 85 years (odds ratio [OR], 4.48), location in the head and neck region (OR, 3.38), presence of solar elastosis in the peritumoral tissue (OR, 2.08), a higher tumor growth rate (>1.5 mm·wk(-1); OR, 5.73), and higher cumulative exposure to smoking (>20 pack-years, OR, 3.63). CONCLUSIONS: Advanced age, location in the head and neck region, presence of solar elastosis, high tumor growth rate, and high cumulative smoking exposure were all significantly associated with the presence of SCC T2.


Subject(s)
Carcinoma, Squamous Cell/pathology , Skin Neoplasms/pathology , Age Factors , Aged , Aged, 80 and over , Anthropometry , Carcinoma, Squamous Cell/epidemiology , Comorbidity , Female , Head and Neck Neoplasms/epidemiology , Head and Neck Neoplasms/pathology , Humans , Keratosis, Actinic/epidemiology , Male , Neoplasm Staging , Neoplasms, Radiation-Induced/pathology , Risk Factors , Skin Neoplasms/epidemiology , Skin Pigmentation , Smoking/adverse effects , Smoking/epidemiology , Spain/epidemiology , Tumor Burden
8.
Br J Nutr ; 111(4): 616-24, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24124655

ABSTRACT

Poor maternal nutrition predisposes offspring to metabolic disease. This predisposition is modified by various postnatal factors. We hypothesised that coupled to the initial effects of developmental programming due to a maternal low-protein diet, a second hit resulting from increased offspring postnatal sugar consumption would lead to additional changes in metabolism and adipose tissue function. The objective of the present study was to determine the effects of sugared water consumption (5% sucrose in the drinking-water) on adult offspring adiposity as a 'second hit' following exposure to maternal protein restriction during pregnancy. We studied four offspring groups: (1) offspring of mothers fed the control diet (C); (2) offspring of mothers fed the restricted protein diet (R); (3) offspring of control mothers that drank sugared water (C-S); (4) offspring of restricted mothers that drank sugared water (R-S). Maternal diet in pregnancy was considered the first factor and sugared water consumption as the second factor - the second hit. Body weight and total energy consumption, before and after sugared water consumption, were similar in all the groups. Sugared water consumption increased TAG, insulin and cholesterol concentrations in both the sexes of the C-S and R-S offspring. Sugared water consumption increased leptin concentrations in the R-S females and males but not in the R offspring. There was also an interaction between sugared water and maternal diet in males. Sugared water consumption increased adipocyte size and adiposity index in both females and males, but the interaction with maternal diet was observed only in females. Adiposity index and plasma leptin concentrations were positively correlated in both the sexes. The present study shows that a second hit during adulthood can amplify the effects of higher adiposity arising due to poor maternal pregnancy diet in an offspring sex dependent fashion.


Subject(s)
Adiposity/drug effects , Diet, Protein-Restricted/adverse effects , Dietary Proteins/administration & dosage , Dietary Sucrose/adverse effects , Obesity/etiology , Prenatal Exposure Delayed Effects , Prenatal Nutritional Physiological Phenomena , Animals , Cholesterol/blood , Dietary Proteins/pharmacology , Female , Insulin/blood , Leptin/blood , Obesity/blood , Pregnancy , Rats , Sex Factors , Triglycerides/blood
9.
Heliyon ; 10(10): e31262, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38818210

ABSTRACT

Dust events in the Canary Islands have been documented since the late 19th century. However, during the past few years, several severe dust episodes have occurred in the Canary Islands, resulting in significant impacts on various sectors, such as aviation, air quality, and health, among others. These recent severe events have drawn the attention of both scientists and the general population, raising questions about whether these episodes are now more frequent and more severe. This study analyzes 483 dust events recorded in the Canary Islands over the last 40 years. Data analysis reveals that the average number of dust event days per year is approximately 24 days, and these events have an average duration of 1.8 days, both of which show a statistically significant decreasing trend over the series. Seasonal examination indicates that events occurring in the first and fourth quarters of the year have twice the duration of those in the other quarters. Furthermore, on an annual basis, events in the first quarter exhibit negative trends in both average and minimum visibilities. This suggests that dust events in the Canary Islands are becoming shorter in duration but more intense in terms of visibility. In this article, the Dust Adversity Index (DAI) is introduced to objectively compare the severity of events. Finally, anomalies in geopotential have been utilized to determine the prevailing synoptic patterns during dust events. It is evident that the dominant synoptic pattern during the first and fourth quarters of the year consists of a low cut-off system located to the west of the Canary Islands and a high-pressure system to the north of the Iberian Peninsula.

10.
Actas Dermosifiliogr ; 104(2): 156-8, 2013 Mar.
Article in English, Spanish | MEDLINE | ID: mdl-22551703

ABSTRACT

Local anesthetics are widely used in clinical practice, and adverse effects are not uncommon. Delayed hypersensitivity reactions are among the most common effects, but immediate-type reactions may also occur. Patch testing should be considered in patients with hypersensitivity reactions. We present a case of allergic contact dermatitis to benzocaine that was detected incidentally by patch testing and highlight the importance of correctly interpreting patch test results when there are concomitant positive reactions.


Subject(s)
Anesthetics, Local/adverse effects , Benzocaine/adverse effects , Dermatitis, Allergic Contact/diagnosis , Dermatitis, Allergic Contact/etiology , Patch Tests , Female , Humans , Middle Aged
12.
Oncology ; 78(3-4): 196-204, 2010.
Article in English | MEDLINE | ID: mdl-20414008

ABSTRACT

OBJECTIVE: Although downregulation of neural cell adhesion molecule (NCAM) has been correlated with poor prognosis in colorectal cancer (CRC), it is also possible that colon cancer spreading comes from reducing tumor cell adhesion through NCAM polysialylation, as occurs in lung carcinoma or Wilms' tumor. METHODS: To prove this hypothesis, we have performed a prospective study on tumor and control specimens from 39 CRC patients, which were immunostained for NCAM and PSA (polysialic acid) expression. RESULTS: Tumor versus control expression of NCAM and PSA epitopes in tissue specimens, as well as correlation between tumor expression and clinicopathological features, were statistically analyzed. Results showed a low constitutive expression of NCAM and PSA (PSA-NCAM) in control tissue, which reached a statistically significant increase in the tumor tissue. Likewise, the presence and number of lymph node metastases at surgery were correlated with NCAM expression and PSA/NCAM coexpression. CONCLUSIONS: These data highlight the importance of taking into account PSA-associated epitopes when dealing with NCAM cell expression studies in tumor development and progression. The analysis of PSA and NCAM expression in CRC suggests a new way, other than downregulation of NCAM, in order to escape contact inhibition and promote cell tumor spreading in colorectal cancer.


Subject(s)
Colorectal Neoplasms/pathology , Neurons/cytology , Aged , Cell Adhesion , Cell Adhesion Molecules , Disease Progression , Epitopes , Female , Humans , Immunohistochemistry/methods , Lymphatic Metastasis , Male , Middle Aged , Models, Statistical , Neoplasm Invasiveness , Neural Cell Adhesion Molecules/metabolism , Prostate-Specific Antigen/metabolism , Sialic Acids/metabolism
13.
Philos Trans R Soc Lond B Biol Sci ; 375(1810): 20190513, 2020 10 26.
Article in English | MEDLINE | ID: mdl-32892733

ABSTRACT

During the summer of 2018, a widespread drought developed over Northern and Central Europe. The increase in temperature and the reduction of soil moisture have influenced carbon dioxide (CO2) exchange between the atmosphere and terrestrial ecosystems in various ways, such as a reduction of photosynthesis, changes in ecosystem respiration, or allowing more frequent fires. In this study, we characterize the resulting perturbation of the atmospheric CO2 seasonal cycles. 2018 has a good coverage of European regions affected by drought, allowing the investigation of how ecosystem flux anomalies impacted spatial CO2 gradients between stations. This density of stations is unprecedented compared to previous drought events in 2003 and 2015, particularly thanks to the deployment of the Integrated Carbon Observation System (ICOS) network of atmospheric greenhouse gas monitoring stations in recent years. Seasonal CO2 cycles from 48 European stations were available for 2017 and 2018. Earlier data were retrieved for comparison from international databases or national networks. Here, we show that the usual summer minimum in CO2 due to the surface carbon uptake was reduced by 1.4 ppm in 2018 for the 10 stations located in the area most affected by the temperature anomaly, mostly in Northern Europe. Notwithstanding, the CO2 transition phases before and after July were slower in 2018 compared to 2017, suggesting an extension of the growing season, with either continued CO2 uptake by photosynthesis and/or a reduction in respiration driven by the depletion of substrate for respiration inherited from the previous months due to the drought. For stations with sufficiently long time series, the CO2 anomaly observed in 2018 was compared to previous European droughts in 2003 and 2015. Considering the areas most affected by the temperature anomalies, we found a higher CO2 anomaly in 2003 (+3 ppm averaged over 4 sites), and a smaller anomaly in 2015 (+1 ppm averaged over 11 sites) compared to 2018. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.


Subject(s)
Atmosphere/analysis , Carbon Cycle , Carbon Dioxide/analysis , Droughts , Ecosystem , Europe
14.
Neuroscience ; 158(4): 1378-89, 2009 Feb 18.
Article in English | MEDLINE | ID: mdl-19038313

ABSTRACT

During embryo neurogenesis, neurons that originate from stem cells located in the forebrain subventricular zone (SVZ) continuously migrate to the olfactory bulb (OB). However, other authors describe the occurrence of resident stem cells in the OB. In the present work we report that the absence of tumor suppressor protein p53 increases the number of neurosphere-forming cells and the proliferation of stem cells derived from 13.5-day embryo OB. Interestingly, differentiation of p53 knockout-derived neurospheres was biased toward neuronal precursors, suggesting a role for p53 in the differentiation process. Moreover, we demonstrate the relevance of p53 in maintaining chromosomal stability in response to genotoxic insult. Finally, our data show that neurosphere stem cells are highly resistant to long-term epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) deprivation in a p53-independent fashion, and they preserve their differentiation potential. Thus, these data demonstrate that p53 controls the proliferation, chromosomal stability and differentiation pattern of embryonic mouse olfactory bulb stem cells.


Subject(s)
Cell Differentiation/genetics , Neurogenesis/genetics , Neurons/physiology , Stem Cells/physiology , Tumor Suppressor Protein p53/physiology , Animals , Annexins/metabolism , Cell Cycle/genetics , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Cells, Cultured , Chromosome Aberrations/radiation effects , Embryo, Mammalian , Epidermal Growth Factor/deficiency , Fibroblast Growth Factor 2/deficiency , Flow Cytometry/methods , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Developmental/genetics , Glial Fibrillary Acidic Protein/metabolism , In Situ Nick-End Labeling/methods , Mice , Mice, Inbred C57BL , Mice, Knockout , Neurogenesis/drug effects , Neurons/drug effects , Neurons/radiation effects , O Antigens/metabolism , Olfactory Bulb/cytology , Protein Binding , Time Factors , Tubulin/metabolism , Tumor Suppressor Protein p53/deficiency , X-Rays/adverse effects
15.
Cancer Invest ; 27(2): 149-55, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19235586

ABSTRACT

The present study was undertaken to validate the antitumor potential of Gymnosperma glutinosum from regional people's account, using the in vitro and in vivo L5178Y-R lymphoma murine model. Non-polar G. glutinosum crude extracts were tested on L5178Y-R cells. We found significant (p < 0.05) cytotoxic activity (up to 40%) of the hexane extract, which was further fractioned; fraction 1 (F1) was then observed to produce up to 51% apoptosis-mediated L5178Y-R cytotoxicity in vitro at concentrations lower than 0.98 microg/ml, and possess significant in vivo antitumor activity. This study may support further evaluation of active F1 in clinical trials.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Asteraceae , Plant Extracts/pharmacology , Plant Leaves/chemistry , Animals , Apoptosis/drug effects , Cell Line, Tumor , Female , Mice , Mice, Inbred BALB C , Mice, Inbred DBA
16.
J Evol Biol ; 21(4): 1117-24, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18462314

ABSTRACT

An enduring puzzle in gynodioecious species is the great variation in female frequency seen among populations. We quantified sex ratio in 44 populations of gynodioecious Kallstroemia grandiflora. Then, we measured pollinator visitation, pollen deposition, autonomous selfing rate and pollen limitation of females. Finally, using experimental populations, we tested whether female fitness responds to the frequency of female plants. We found broad variability in sex ratio among populations (0-44% female). Hermaphrodite flowers received more pollinator visits and pollen grains than females, and bagged hermaphrodite flowers produced fruits. However, we found no evidence of pollen limitation in females. In experimental populations, female plants showed no evidence of frequency-dependent pollinator visitation, fruit set, seed set or total seed mass. These results do not support frequency-dependent variation in fitness as a major mechanism affecting female frequencies in K. grandiflora. Within the context of this study, pollinators are abundant and pollinator movement appears to operate at a large enough scale to overcome the potential reproductive disadvantages of producing solely female flowers.


Subject(s)
Zygophyllaceae/anatomy & histology , Zygophyllaceae/physiology , Ecology , Fruit , Mexico , Pollen , Reproduction/physiology , Seeds , Sex Ratio
18.
Plant Biol (Stuttg) ; 20(1): 160-164, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29069524

ABSTRACT

In sexually dimorphic species, hermaphrodite flowers in gynodioecious species or male flowers in dioecious species are often larger and produce more nectar than their conspecific female flowers. As a consequence, hermaphrodite or male flowers frequently receive more pollinator visits. Sex ratio, flower size, floral display, nectar production and floral visits were evaluated in two natural populations of Fuchsia thymifolia, a morphologically gynodioecious but functionally subdioecious insect-pollinated shrub. Sex ratio did not differ from the expected 1:1 in the two studied populations. As expected, hermaphrodite flowers were larger than female flowers, but in contrast to the general pattern, hermaphrodite flowers did not produce nectar or produced much less than female flowers. Flower visitors were flies (68%) and bumblebees (24%), both of which showed a preference for female flowers. No sex difference was detected in either flower longevity or floral display across the flowering season. Higher nectar production by females may attract more pollinators, and may be a strategy to enhance female reproductive success in this species. Finally, floral dimorphism and insect preferences did not seem to hamper the maintenance of sub-dioecy or prevent the evolution of dioecy in F. thymifolia.


Subject(s)
Flowers/physiology , Onagraceae/physiology , Plant Nectar/metabolism , Pollination , Sex Characteristics , Flowers/anatomy & histology , Onagraceae/anatomy & histology , Pollination/physiology , Sex Ratio
19.
Plant Biol (Stuttg) ; 20(6): 1075-1082, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30004608

ABSTRACT

The integrity of species in sympatric contact sites is dependent on the existence of reproductive isolating mechanisms, which restrict gene flow between them. However, we know little about the mechanisms that enable the coexistence of species with similar floral morphologies. Here, we evaluated several reproductive isolation barriers between Salvia elegans and S. fulgens, two sympatric sages with a similar ornithophilous floral syndrome, offering nectar as the main reward. Over 3 years, we evaluated broad-scale geographic isolation, floral phenologies and floral visitors as pre-pollination barriers, and fruit set, seed number and seed germination as post-pollination barriers. We found considerable geographic isolation and significant altitudinal differences between the two sages. The flowering period of both sages always overlapped extensively during the 3 years of this study, but hummingbirds were highly specific, visiting one or the other Salvia species and showing aggressive territorial behaviour. Interspecific experimental crosses revealed that hybrid seeds might be formed although strong asymmetric barriers were found depending on the species acting as the maternal donor. Despite the low level of flowering asynchrony, reproductive isolation was remarkably high in the two sages. Geographic isolation and pollinator fidelity were the main factors responsible for maintaining species integrity. Despite an extensive review, we found very few studies quantifying the efficiency of isolation barriers in Neotropical plants or even the importance of hummingbirds as pollinators.


Subject(s)
Birds/physiology , Pollination/physiology , Reproductive Isolation , Salvia/physiology , Sympatry/physiology , Altitude , Animals , Flowers/physiology
20.
Neurosci Lett ; 670: 105-109, 2018 03 23.
Article in English | MEDLINE | ID: mdl-29391219

ABSTRACT

Evoked EMG reflex activity from the pubococcygeus muscle of female Wistar rats has been reported, but has not been carefully analyzed. Here, we studied this reflex activity through mechanical stimulation of the clitoris, perigenital skin, caudal vagina and foot, all of which produced bilateral reflex multiunit electromyographic (MEMG) tonic "on" activity and displayed a rapid adaptation. However, deep vagina and cervical stimulation did not modify MEMG baseline activity even if it was combined with clitoris, perigenital skin and foot stimulation. Electrical stimulation of the dorsal nerve of the clitoris produced bilateral MEMG activity that when recorded at fast sweep speed, it was possible to observe that the ipsilateral response had an 8 ms latency, while the contralateral response had a 10 ms latency. These data suggest that bilateral reflex activation of pubococcygeus muscle motoneurons is produced by several sensory sources in which a specialized neural circuitry of afferent and efferent components and several spinal cord interneurons are involved. This is in accordance with the multi functionality of this muscle in reproductive and behavioral processes.


Subject(s)
Motor Neurons/physiology , Neurons/physiology , Pelvic Floor/innervation , Reflex/physiology , Spinal Cord/physiology , Animals , Electric Stimulation , Electromyography , Female , Muscle, Skeletal/physiology , Rats , Rats, Wistar
SELECTION OF CITATIONS
SEARCH DETAIL