scholarly journals Evidence for interspecific hybridization in bryophytes during pre-molecular and molecular eras

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
WEERACHON SAWANGPROH ◽  
NILS CRONBERG
Keyword(s):  
Molecular Marker ◽  
Interspecific Hybridization ◽  
Vascular Plants ◽  
Evolutionary Process ◽  
Hybrid Speciation ◽  
Future Studies ◽  
Molecular Approaches ◽  
Allopolyploid Speciation ◽  
Before And After ◽  
Evolutionary Consequences

Interspecific hybridization had been long recognized as a widespread evolutionary process in vascular plants. In the present review, we summarize knowledge concerning studies of interspecific hybridization in bryophytes before and after the advent of molecular methods. The available data indicate that hybridization is an important evolutionary phenomenon among bryophytes. Evidence for hybridization events before the molecular era is mainly based on studies of intermediacy of parental morphology. The recent molecular marker technology has revolutionized studies of hybridization, generating new insights into the genetic and evolutionary consequences of homoploid and allopolyploid speciation. The current molecular approaches support the prevalence of allopolyploidy in bryophytes. However, we anticipate that homoploid hybridization is under-reported. Finally, we suggest some directions for future studies of hybrid speciation among bryophytes.

Allopolyploid Speciation Accompanied by Gene Flow in a Tree Fern

2020 ◽  
Vol 37 (9) ◽  
pp. 2487-2502 ◽  
Author(s):  
Jing Wang ◽  
Shiyong Dong ◽  
Lihua Yang ◽  
Aj Harris ◽  
Harald Schneider ◽  
...  
Keyword(s):  
Gene Flow ◽  
East Asian Monsoon ◽  
Southern China ◽  
Evolutionary Process ◽  
Data Sets ◽  
Hybrid Speciation ◽  
Tree Fern ◽  
Hybrid Species ◽  
Allopolyploid Speciation ◽  
New Perspective

Abstract Hybridization in plants may result in hybrid speciation or introgression and, thus, is now widely understood to be an important mechanism of species diversity on an evolutionary timescale. Hybridization is particularly common in ferns, as is polyploidy, which often results from hybrid crosses. Nevertheless, hybrid speciation as an evolutionary process in fern lineages remains poorly understood. Here, we employ flow cytometry, phylogeny, genomewide single nucleotide polymorphism data sets, and admixture and coalescent modeling to show that the scaly tree fern, Gymnosphaera metteniana is a naturally occurring allotetraploid species derived from hybridization between the diploids, G. denticulata and G. gigantea. Moreover, we detected ongoing gene flow between the hybrid species and its progenitors, and we found that G. gigantea and G. metteniana inhabit distinct niches, whereas climatic niches of G. denticulata and G. metteniana largely overlap. Taken together, these results suggest that either some degree of intrinsic genetic isolation between the hybrid species and its parental progenitors or ecological isolation over short distances may be playing an important role in the evolution of reproductive barriers. Historical climate change may have facilitated the origin of G. metteniana, with the timing of hybridization coinciding with a period of intensification of the East Asian monsoon during the Pliocene and Pleistocene periods in southern China. Our study of allotetraploid G. metteniana represents the first genomic-level documentation of hybrid speciation in scaly tree ferns and, thus, provides a new perspective on evolution in the lineage.

scholarly journals Susceptible trichostrongyloid species mask presence of benzimidazole-resistant Haemonchus contortus in cattle

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Khalid M. Mohammedsalih ◽  
Jürgen Krücken ◽  
Ahmed Bashar ◽  
Fathel-Rahman Juma ◽  
Abdalhakaim A. H. Abdalmalaik ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Epidemiological Data ◽  
Nematode Species ◽  
Parasitic Nematodes ◽  
Molecular Approaches ◽  
Tubulin Genes ◽  
Faecal Egg Count ◽  
Third Stage ◽  
Before And After ◽  
Β Tubulin

Abstract Background Benzimidazole (BZ) anthelmintics are widely used to control infections with parasitic nematodes, but BZ resistance is an emerging threat among several nematode species infecting humans and animals. In Sudan, BZ-resistant Haemonchus contortus populations were recently reported in goats in South Darfur State. The objective of this study was to collect data regarding the situation of BZ resistance in cattle parasitic nematodes in South Darfur using phenotypic and molecular approaches, besides providing some epidemiological data on nematodes in cattle. Methods The faecal egg count reduction test and the egg hatch test (EHT) were used to evaluate benzimidazole efficacy in cattle nematodes in five South Darfur study areas: Beleil, Kass, Nyala, Rehed Al-Birdi and Tulus. Genomic DNA was extracted from pools of third-stage larvae (L3) (n = 40) during trials, before and after treatment, and pools of adult male Haemonchus spp. (n = 18) from abattoirs. The polymorphisms F167Y, E198A and F200Y in isotype 1 β-tubulin genes of H. contortus and H. placei were analysed using Sanger and pyrosequencing. Results Prevalence of gastro-intestinal helminths in cattle was 71% (313/443). Reduced albendazole faecal egg count reduction efficacy was detected in three study areas: Nyala (93.7%), Rehed Al-Birdi (89.7%) and Tulus (88.2%). In the EHT, EC50 values of these study areas ranged between 0.032 and 0.037 µg/ml thiabendazole. Genus-specific PCRs detected the genera Haemonchus, Trichostrongylus and Cooperia in L3 samples collected after albendazole treatment. Sanger sequencing followed by pyrosequencing assays did not detect elevated frequencies of known BZ resistance-associated alleles in codon F167Y, E198A and F200Y in isotype 1 β-tubulin gene of H. placei (≤ 11.38%). However, polymorphisms were detected in H. contortus and in samples with mixed infections with H. contortus and H. placei at codon 198, including E198L (16/58), E198V (2/58) and potentially E198Stop (1/58). All pooled L3 samples post-albendazole treatment (n = 13) were identified as H. contortus with an E198L substitution at codon 198. Conclusions To the knowledge of the authors, this is the first report of reduced albendazole efficacy in cattle in Sudan and is the first study describing an E198L substitution in phenotypically BZ-resistant nematodes collected from cattle.

Effectiveness of Combining Manual Therapy and Acupuncture on Temporomandibular Joint Dysfunction: A Retrospective Study

2007 ◽  
Vol 35 (02) ◽  
pp. 203-208 ◽  
Author(s):  
Byung-Cheul Shin ◽  
Chung-Hyo Ha ◽  
Yung-Sun Song ◽  
Myeong Soo Lee
Keyword(s):  
Retrospective Study ◽  
Temporomandibular Joint ◽  
Manual Therapy ◽  
Randomized Clinical Trials ◽  
Combined Treatment ◽  
Mouth Opening ◽  
Temporomandibular Joint Dysfunction ◽  
Future Studies ◽  
Before And After ◽  
Maximal Mouth Opening

This retrospective study investigated the effects of combining manual therapy and acupuncture on the pain and maximal mouth opening (MMO), which were associated with temporomandibular joint dysfunction (TMD). The 49 TMD patients (15 men, 34 women; mean age = 30.47 years, SD = 13.52 years) were treated with a combination of acupuncture and manual therapy two or three times a week at the hospital. The pain and maximal mouth opening were assessed before and after 1 and 4 weeks of treatment. The combination therapy produced significant changes in pain levels ( p < 0.001) and mouth opening ( p < 0.001). All pairwise non-parametric comparison showed a significant improvement in pain ( p < 0.05 for all pairs) and MMO ( p < 0.05 for all pairs). These findings suggest that combining manual therapy and acupuncture decreases the pain level and increases the MMO of TMD patients. However, future studies should further investigate the efficacy of combined treatment on TMD with more rigorous randomized clinical trials.

scholarly journals Comparing Sudden Stratospheric Warming Definitions in Reanalysis Data*

2015 ◽  
Vol 28 (17) ◽  
pp. 6823-6840 ◽  
Author(s):  
Froila M. Palmeiro ◽  
David Barriopedro ◽  
Ricardo García-Herrera ◽  
Natalia Calvo
Keyword(s):  
Seasonal Cycle ◽  
Winter Season ◽  
Reanalysis Data ◽  
Sudden Stratospheric Warming ◽  
Pronounced Increase ◽  
Future Studies ◽  
Common Peak ◽  
Before And After ◽  
The Mean ◽  
Large Case

Abstract Sudden stratospheric warmings (SSWs) are characterized by a pronounced increase of the stratospheric polar temperature during the winter season. Different definitions have been used in the literature to diagnose the occurrence of SSWs, yielding discrepancies in the detected events. The aim of this paper is to compare the SSW climatologies obtained by different methods using reanalysis data. The occurrences of Northern Hemisphere SSWs during the extended-winter season and the 1958–2014 period have been identified for a suite of eight representative definitions and three different reanalyses. Overall, and despite the differences in the number and exact dates of occurrence of SSWs, the main climatological signatures of SSWs are not sensitive to the considered reanalysis. The mean frequency of SSWs is 6.7 events decade−1, but it ranges from 4 to 10 events, depending on the method. The seasonal cycle of events is statistically indistinguishable across definitions, with a common peak in January. However, the multidecadal variability is method dependent, with only two definitions displaying minimum frequencies in the 1990s. An analysis of the mean signatures of SSWs in the stratosphere revealed negligible differences among methods compared to the large case-to-case variability within a given definition. The stronger and more coherent tropospheric signals before and after SSWs are associated with major events, which are detected by most methods. The tropospheric signals of minor SSWs are less robust, representing the largest source of discrepancy across definitions. Therefore, to obtain robust results, future studies on stratosphere–troposphere coupling should aim to minimize the detection of minor warmings.

Psychophysical interactions with a double-slit interference pattern: Exploratory evidence of a causal influence

2021 ◽  
Vol 34 (1) ◽  
pp. 79-88
Author(s):  
Dean Radin ◽  
Helané Wahbeh ◽  
Leena Michel ◽  
Arnaud Delorme
Keyword(s):  
Experimental Data ◽  
Interference Pattern ◽  
Type I Error ◽  
Human Mind ◽  
The Other ◽  
Type I ◽  
Fringe Visibility ◽  
Future Studies ◽  
Before And After ◽  
Double Slit

An experiment we conducted from 2012 to 2013, which had not been previously reported, was designed to explore possible psychophysical effects resulting from the interaction of a human mind with a quantum system. Participants focused their attention toward or away from the slits in a double-slit optical system to see if the interference pattern would be affected. Data were collected from 25 people in individual half-hour sessions; each person repeated the test ten times for a total of 250 planned sessions. “Sham” sessions designed to mimic the experimental sessions without observers present were run immediately before and after as controls. Based on the planned analysis, no evidence for a psychophysical effect was found. Because this experiment differed in two essential ways from similar, previously reported double-slit experiments, two exploratory analyses were developed, one based on a simple spectral analysis of the interference pattern and the other based on fringe visibility. For the experimental data, the outcome supported a pattern of results predicted by a causal psychophysical effect, with the spectral metric resulting in a 3.4 sigma effect (p = 0.0003), and the fringe visibility metric resulting in 7 of 22 fringes tested above 2.3 sigma after adjustment for type I error inflation, with one of those fringes at 4.3 sigma above chance (p = 0.00001). The same analyses applied to the sham data showed uniformly null outcomes. Other analyses exploring the potential that these results were due to mundane artifacts, such as fluctuations in temperature or vibration, showed no evidence of such influences. Future studies using the same protocols and analytical methods will be required to determine if these exploratory results are idiosyncratic or reflect a genuine psychophysical influence.

scholarly journals Field (In)dependence Flexibility Following a Virtual Immersion Is Associated With Cybersickness and Sense of Presence

2021 ◽  
Vol 2 ◽  
Author(s):  
A. Maneuvrier ◽  
L. M. Decker ◽  
P. Renaud ◽  
G. Ceyte ◽  
H. Ceyte
Keyword(s):  
Visual Cues ◽  
Subjective Experience ◽  
A Posteriori ◽  
Future Studies ◽  
Sense Of Presence ◽  
Before And After ◽  
High Level ◽  
Shed Light ◽  
Rod And Frame Test ◽  
Rod And Frame

Field dependence–independence (FDI) is a psychological construct determining an individual’s approach of the perception–cognition coupling. In virtual reality (VR) context, several studies suggest that an individual’s perceptive style is susceptible to shift toward a more FI mode through down-weighting of conflicting visual cues. The present study proposes to investigate the potential flexible nature of FDI following a virtual immersion and to assess if this flexibility might be associated with the subjective experience of VR. 86 participants explored a real-world–like virtual environment for approximately 10 min. FDI levels were measured before and after the VR exposure using the rod-and-frame test. Their subjective experience of VR was measured a posteriori (cybersickness and sense of presence) and used in order to build two experimental groups via a cluster analysis. The results showed that only participants with a poor subjective experience of VR (i.e., a low level of sense of presence associated with a high level of cybersickness) significantly shifted to a more FI mode, which is discussed as a sensory re-weighting mechanism. Pragmatical applications are discussed, and future studies are outlined, based on the conclusion that FDI might be more flexible than we thought, which could shed light on the psychophysiology of VR.

scholarly journals Interspecific hybridization can generate functional novelty in cichlid fish

2019 ◽  
Vol 286 (1913) ◽  
pp. 20191621 ◽  
Author(s):  
O. M. Selz ◽  
O. Seehausen
Keyword(s):  
Interspecific Hybridization ◽  
First Generation ◽  
Parental Species ◽  
Cichlid Fish ◽  
Context Dependency ◽  
Functional Variation ◽  
Generate Functional ◽  
Cichlid Species ◽  
Evolutionary Consequences ◽  
African Cichlids

The role of interspecific hybridization in evolution is still being debated. Interspecific hybridization has been suggested to facilitate the evolution of ecological novelty, and hence the invasion of new niches and adaptive radiation when ecological opportunity is present beyond the parental species niches. On the other hand, hybrids between two ecologically divergent species may perform less well than parental species in their respective niches because hybrids would be intermediate in performance in both niches. The evolutionary consequences of hybridization may hence be context-dependent, depending on whether ecological opportunities, beyond those of the parental species, do or do not exist. Surprisingly, these complementary predictions may never have been tested in the same experiment in animals. To do so, we investigate if hybrids between ecologically distinct cichlid species perform less well than the parental species when feeding on food either parent is adapted to, and if the same hybrids perform better than their parents when feeding on food none of the species are adapted to. We generated two first-generation hybrid crosses between species of African cichlids. In feeding efficiency experiments we measured the performance of hybrids and parental species on food types representing both parental species niches and additional ‘novel’ niches, not used by either of the parental species but by other species in the African cichlid radiations. We found that hybrids can have higher feeding efficiencies on the ‘novel’ food types but typically have lower efficiencies on parental food types when compared to parental species. This suggests that hybridization can generate functional variation that can be of ecological relevance allowing the access to resources outside of either parental species niche. Hence, we provide support for the hypothesis of ecological context-dependency of the evolutionary impact of interspecific hybridization.

Using fMRI to evaluate the effects of milnacipran on central pain processing in patients with fibromyalgia

2013 ◽  
Vol 4 (2) ◽  
pp. 65-74 ◽  
Author(s):  
F. Petzke ◽  
K.B. Jensen ◽  
E. Kosek ◽  
E. Choy ◽  
S. Carville ◽  
...  
Keyword(s):  
Default Mode Network ◽  
Brain Function ◽  
Pain Processing ◽  
Central Pain ◽  
Pressure Pain ◽  
Future Studies ◽  
Default Mode ◽  
Before And After ◽  
Fmri Analysis ◽  
Central Pain Processing

AbstractBackgroundIn recent years, the prescription of serotonin-noradrenalin reuptake inhibitors (SNRIs) for treatment of fibromyalgia (FM) has increased with reports of their efficacy. The SNRI milnacipran is approved by the U.S. Food and Drug Administration (FDA) for treatment of FM, yet, the mechanisms by which milnacipran reduces FM symptoms are unknown. A large number of neuroimaging studies have demonstrated altered brain function in patients with FM but the effect of milnacipran on central pain processing has not been investigated. The primary objective of this study was to assess the effect of milnacipran on sensitivity to pressure-evoked pain in FM. Secondary objectives were to assess the effect of milnacipran on cerebral processing of pressure-evoked pain using fMRI and the tolerability and safety of milnacipran 200 mg/day in FM.Methods92 patients were randomized to either 13-weeks milnacipran treatment (200 mg/day) or placebo in this double-blind, placebo-controlled multicenter clinical trial. Psychophysical measures and functional MRI (fMRI) assessments were performed before and after treatment using a computer-controlled pressure-pain stimulator. Here, we present the results of several a priori defined statistical analyses.ResultsMilnacipran-treated patients displayed a trend toward lower pressure-pain sensitivity after treatment, compared to placebo, and the difference was greater at higher pain intensities. A single group fMRI analysis of milnacipran-treated patients indicated increased pain-evoked brain activity in the caudatus nucleus, anterior insula and amygdala after treatment, compared to before treatment; regions implicated in pain inhibitory processes. A 2 × 2 repeated measures fMRI analysis, comparing milnacipran and placebo, before and after treatment, showed that milnacipran-treated patients had greater pain-evoked activity in the precuneus/posterior cingulate cortex after treatment; a region previously implicated in intrinsic brain function and FM pathology. This finding was only significant when uncorrected for multiple comparisons. The safety analysis revealed that patients from both treatment groups had treatment-emergent adverse events where nausea was the most common complaint, reported by 43.5% of placebo patients and 71.7% of milnacipran-treated patients. Patients on milnacipran were more likely to discontinue treatment because of side effects.ConclusionsOur results provide preliminary indications of increased pain inhibitory responses in milnacipran-treated FM patients, compared to placebo. The psychophysical assessments did not reach statistical significance but reveal a trend toward higher pressure-pain tolerance after treatment with milnacipran, compared to placebo, especially for higher pain intensities. Our fMRI analyses point toward increased activation of the precuneus/posterior cingulum in patients treated with milnacipran, however results were not corrected for multiple comparisons. The precuneus/posterior cingulum is a key region of the default mode network and has previously been associated with abnormal function in FM. Future studies may further explore activity within the default mode network as a potential biomarker for abnormal central pain processing.ImplicationsThe present study provides novel insights for future studies where functional neuroimaging may be used to elucidate the central mechanisms of common pharmacological treatments for chronic pain. Furthermore, our results point toward a potential mechanism for pain normalization in response to milnacipran, involving regions of the default mode network although this finding needs to be replicated in future studies.

scholarly journals Stability-based sorting: The forgotten process behind (not only) biological evolution

2017 ◽  
Author(s):  
Jaroslav Flegr ◽  
Jan Toman
Keyword(s):  
Natural Selection ◽  
Biological Evolution ◽  
Evolutionary Process ◽  
Static Stability ◽  
Main Process ◽  
Strict Sense ◽  
Broad Distribution ◽  
Evolutionary Consequences ◽  
Insight Into

AbstractNatural selection is considered to be the main process that drives biological evolution. It requires selected entities to originate dependent upon one another by the means of reproduction or copying, and for the progeny to inherit the qualities of their ancestors. However, natural selection is a manifestation of a more general persistence principle, whose temporal consequences we propose to name “stability-based sorting” (SBS). Sorting based on static stability, i.e., SBS in its strict sense and usual conception, favours characters that increase the persistence of their holders and act on all material and immaterial entities. Sorted entities could originate independently from each other, are not required to propagate and need not exhibit heredity. Natural selection is a specific form of SBS—sorting based on dynamic stability. It requires some form of heredity and is based on competition for the largest difference between the speed of generating its own copies and their expiration. SBS in its strict sense and selection thus have markedly different evolutionary consequences that are stressed in this paper. In contrast to selection, which is opportunistic, SBS is able to accumulate even momentarily detrimental characters that are advantageous for the long-term persistence of sorted entities. However, it lacks the amplification effect based on the preferential propagation of holders of advantageous characters. Thus, it works slower than selection and normally is unable to create complex adaptations. From a long-term perspective, SBS is a decisive force in evolution—especially macroevolution. SBS offers a new explanation for numerous evolutionary phenomena, including broad distribution and persistence of sexuality, altruistic behaviour, horizontal gene transfer, patterns of evolutionary stasis, planetary homeostasis, increasing ecosystem resistance to disturbances, and the universal decline of disparity in the evolution of metazoan lineages. SBS acts on all levels in all biotic and abiotic systems. It could be the only truly universal evolutionary process, and an explanatory framework based on SBS could provide new insight into the evolution of complex abiotic and biotic systems.

scholarly journals Effect of a Precision Cryotherapy Device With Temperature- Adjustability on Mice With Lysophosphatidic Acid-Induced Pruritus

2021 ◽  
Author(s):  
Mi Hee Kwack ◽  
Seongjin Lee ◽  
Han Jin jung ◽  
Gi Ung Ha ◽  
Gun-Ho Kim ◽  
...  
Keyword(s):  
Lysophosphatidic Acid ◽  
Adverse Impact ◽  
Complex Mechanism ◽  
Inflammatory Skin Disease ◽  
Chain Reaction ◽  
Future Studies ◽  
Chronic Itch ◽  
Before And After ◽  
Polymerase Chain

Abstract Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease that is known to cause a significant adverse impact on the quality of life of patients. Reducing chronic itch that has a complex mechanism is one of the most important challenges in AD treatment.Objective: To evaluate the effect of a temperature-adjustable cryotherapy device on mice with lysophosphatidic acid-induced pruritus.Methods: A temperature and time-adjustable cryotherapy device was used for the treatment of lysophosphatidic acid-induced pruritus of mice in the following conditions: −5℃, 0℃, or 5℃ for 5 sec, 10 sec, or 20 sec. Expression of itch-related biomarkers before and after modulation of temperature was investigated with real-time polymerase chain reaction (PCR) and immunohistochemistry.Results: Expression of itch-related biomarkers was decreased after modulation of temperature. For gene expression, all were decreased at 5℃ for 10 sec and 20 sec, and at 0℃ for 5 sec, 10 sec, and 20 sec. For protein expression, all were decreased at 5℃ for 10 sec and 20 sec, and at 0℃ for 5 sec and 10 sec.Conclusion: This study demonstrates the pruritus-relieving effect of the temperature-adjustable device on mice. This may provide some evidence for future studies on patients with mild AD.

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