Each Nutlin-3 supplier assembly is a neural network with no delay in the local couplings between the units. The delay appears in the long range feedforward and feedback inter-assemblies communications. Bifurcation analysis of a simple four-units system in the autonomous case shows the richness of the dynamical behaviors in a biophysically plausible parameter region. We find oscillatory multistability, hysteresis, and stability switches of the rest state provoked by the time delay. Then we investigate the spatio-temporal patterns of bifurcating periodic solutions by using the symmetric local Hopf bifurcation theory of delay differential

equations and derive the equation describing the flow on the center manifold that enables us determining the direction of Hopf bifurcations and stability of the bifurcating periodic see more orbits. We also discuss computational properties of the system due to the delay when an external drive of the network mimicks external sensory input.”
“To improve denitrification performance and effective degradation of organic pollutants from micro-polluted groundwater simultaneously, a novel three-dimensional

(3D) bio-electrochemical reactor was developed, which introduced activated carbon into a traditional two-dimensional (2D) reactor as the third electrode. The static and dynamic characteristics of the reactor were investigated with special attentions paid to the performance comparison of these two reactors. In the 3D reactor both TOC and nitrate removal efficiency were greatly improved,

and the formation of nitrite byproduct is considerably reduced, comparing with that of the 2D reactor. The role of activated carbon biofilm NF-��B inhibitor was explored and possible remediation mechanisms for the 2D and 3D reactors were suggested. In such a 3D reactor, the denitrification rate improved greatly to 0.288 mg NO3-NJcm(2)/d and the current efficiency could reach as high as 285%. Further, it demonstrated good performance stably against variable conditions, indicating very promising in application for groundwater remediation. (C) 2009 Published by Elsevier Ltd.”
“Objective: To determine the efficacy and safety of deferasirox (an oral iron-chelating agent approved to reduce iron stores in patients with chronic iron overload due to blood transfusions) in a pilot trial for the treatment of patients with porphyria cutanea tarda (PCT), the most common of the porphyrias and often difficult to treat.\n\nDesign: Prospective, open-label, noncomparative study.\n\nSetting: University-affiliated tertiary health care center in Dallas, Texas.\n\nPatients: Ten patients with PCT were enrolled in this 6-month study. The diagnosis was established by documenting the presence of elevated porphyrin level in the urine and a history of developing 3 or more blisters per month for at least 3 months prior to enrollment. Patients were treated with 250 mg/d of deferasirox, with an increase to 500 mg/d after 2 months if new blisters continued to develop.

A hybrid imaging agent targeting the av beta 3 integrin111In-MSAP-RGD (MSAP=multifunctional single-attachment-point reagent), which contains a targeting moiety, a pentetic acid (DTPA) chelate, and a cyanine selleck compound dyewas evaluated for its potential value in combined lesion detection and interventional molecular imaging in a 4T1 mouse breast cancer model. SPECT/CT and fluorescence imaging were used to visualize the tumor in vivo. Tracer distribution was evaluated ex vivo down to the microscopic level. The properties of 111In-MSAP-RGD were compared with those of 111In-DTPA-RGD. Biodistribution studies revealed a prolonged retention and increased tumor accumulation of 111In-MSAP-RGD

relative to 111In-DTPA-RGD. With 111In-MSAP-RGD, identical features could be visualized preoperatively (SPECT/CT) and intraoperatively (fluorescence imaging). As well as the primary tumor, 111In-MSAP-RGD also enabled detection and accurate excision of distant metastases in the head and neck region of the mice. Therefore, the hybrid RGD derivative 111In-MSAP-RGD shows potential in preoperative planning and fluorescence-based surgical

intervention.”
“There are no data indicating a clear relationship between the clinical effect of risperidone and plasma drug concentration. In this study, 51 patients with acutely exacerbated schizophrenia received 6 mg risperidone/day for 4 weeks. A clinical evaluation using the Brief Psychiatric Rating Scale (BPRS) and PD173074 Udvalg for Klinicke Undersogelser (UKU) side effect rating scale were performed at baseline and each week. Significant (P < 0.05) correlations were found between plasma concentrations of risperidone and improved total selleck inhibitor BPRS scores, positive and cognitive symptoms. Plasma

concentrations of the active moiety were significantly (P < 0.05) correlated with improved total BPRS scores. Improved score and percent improvement in anxiety-depression subscale were significantly (P < 0.01) correlated with plasma concentrations of the active moiety. The sum of total UKU side effect scores from 1 to 4 weeks was significantly correlated with plasma concentration of both risperidone (rs = 0.319, P < 0.05) and active moiety (rs = 0.373, P < 0.01). The sum of the psychic subgroup scores was significantly correlated with plasma concentrations of active moiety (rs = 0.318, P < 0.05). Results suggest that plasma drug concentrations are, to some extent, associated with improved scores in some psychopathological schizophrenic symptoms and sedative side effects. These findings should be replicated with a larger patient sample.”
“QRS Fragmentation and the Risk of Sudden Cardiac Death in MADIT II. Background: QRS fragmentation (fQRS) has been reported as a useful ECG parameter in predicting mortality in high-risk postinfarction patients. Its prognostic value for sudden cardiac death (SCD) and ventricular arrhythmias in ischemic cardiomyopathy (ICM) remains unknown.

Here, we first review the role of the cell cycle in pituitary tumorigenesis, as witnessed by human pathology and transgenic mice; and then, we focus on HMGA proteins and their cell cycle-related role in pituitary tumorigenesis. Journal of Molecular Endocrinology (2010) 44, 309-318″
“Lonomia obliqua envenomation is characterized by intense local inflammatory reaction, which, dependent on the severity of the case, is followed by severe clinical manifestations related to hemorrhagic disorders that can lead to fatal outcome. These effects see more were imputed to several toxins present in L obliqua venom,

which are responsible for procoagulant, anticoagulant check details as well as antithrombotic activities, being also able to interfere with vascular cells functions. In this work, the intravital microscopy analysis show that after administration of low doses of L. obliqua venom (1-3 mu g/ml) on hamster cheek pouch, there was no alterations neither

on arterioles or venules caliber nor in the vascular permeability up to 30 min. However, after 10 min in contact with venom occurred a clear activation in the vascular bed, characterized by an increase in leukocyte rolling and adhesion on endothelium of hamster cheek pouch venules. A confocal analysis of vascular beds, confirmed these results showing an increase in endothelial E-selectin and VCAM-1 expression. The effects of L. obliqua venom https://www.selleckchem.com/products/ganetespib-sta-9090.html on human endothelial cell (EC) in vitro were also investigated.

The treatment of EC with venom (1-3 mu g/ml) did not affect cell viability. However, at concentrations as low as 3 mu g/ml of L. obliqua venom modifies actin cytoskeleton dynamics, and increases focal adhesion contacts, inducing stress fiber formation, focal adhesion kinase (FAK) phosphorylation and its subsequent association to actin. These effects are followed by the activation of NF-kappa B pathway, a critical signaling in several events associated to vascular inflammation. Accordingly, L. obliqua venom leads to a significant increase in COX-2, NOS-2, HO-1, MMP-2 and MMP-9 expression. Taken together the data show that, even at low concentrations, L. obliqua venom can activate endothelial cells, which assume a pro-inflammatory profile, contributing for local effects and probably also for systemic disturbances due to its ability to modulate the properties of the vascular system. (c) 2012 Elsevier Ltd. All rights reserved.”
“The long-term response, including recovery, of aquatic macroinvertebrates to short-term insecticide exposure may be affected by the presence of uncontaminated refuges in the stressed ecosystem.

01). Following recent APM, people may adapt their gait to protect the operated knee from excessive loads, as evidenced by a lower maximum loading rate in the APM leg compared to controls, and a reduced peak F-z in the APM leg compared to the non-APM leg. No differences at follow-up may suggest an eventual return to more typical gait. However, the increase in peak F-z in the APM leg may be of concern for long-term joint health given the compromised function of the meniscus. (C) 2014 Elsevier Ltd. All rights reserved.”
“Background: This study investigated the potential involvement of

Axl signaling in polarization of tumor-associated macrophages (TAMs) in oral squamous cell carcinoma (OSCC). Methods: Condition medium (CM) from OSCC cells (OEC-M1 and YD38) were collected and their effects

on macrophage HSP990 (THP-1) polarization were examined. Modulation of Axl, PI3/Akt, and NF-kappa B were performed selleck kinase inhibitor to investigate their potential involvement in TAM polarization. Expression of pAxl and CD206 were analyzed by immunohistochemistry in OSCC tissues. Results: THP-1 polarized to M2 phenotype with increasing expression of interleukins, vascular endothelial growth factor, matrix metalloproteinase and CD206 upon treatment with CM of OSCC. Activated Axl signaling in OSCC enhanced M2 induction ability. Suppression of Axl signaling and inhibition of PI3/Akt and NF-kappa B diminished M2 induction. pAxl expression was significantly associated with distribution of CD206

positive cells in OSCC tissues. Conclusion: Axl signaling of OSCC involved in polarizing TAMs toward M2 phenotype. Induction of M2 phenotype macrophage polarization by OSCC cells might involve the Axl/PI3/Akt/NF-kappa B pathway. (C) 2015 Elsevier Ltd. All rights reserved.”
“The glucagonlike peptide 1 receptor (GLP-1R) is mainly expressed on beta-cells in the Wets of Langerhans and is therefore an attractive target for imaging of the beta-cell mass. In the present study, Ga-68-labeled exendin-4 was evaluated for PET imaging and quantification of GLP-1R in the pancreas. Methods: Dose https://www.selleckchem.com/products/pf299804.html escalation studies of Ga-68-labeled 1,4,7-tris(carboxymethylaza)cyclododecane-10-azaacetyl (DO3A)-exendin-4 were performed in rats (organ distribution) and cynomolgus monkeys (PET/CT imaging) to determine the GLP-1R-specific tissue uptake in vivo. Pancreatic uptake (as determined by organ distribution) in healthy rats was compared with that in diabetic rats. GLP-1R occupancy in the cynomolgus pancreas was quantified with a 1-tissue-compartment model. Results: In rodents, uptake in the pancreas was decreased from the baseline by up to 90% (P < 0.0001) by coadministration of DO3A-exendin-4 at 100 mu g/kg. Pancreatic uptake in diabetic animals was decreased by more than 80% (P < 0.001) compared with that in healthy controls, as measured by organ distribution. GLP-1R occupancy in the cynomolgus pancreas after coinjection of DO3A-exendin-4 at 0.

Low baseline CD4 cell count < 100 cells/L was significantly related with HIV-related ophthalmic manifestations and CMV retinitis at presentation (P < 0.013). 105 patients were followed for 6 months or more and the mean follow-up was 4.8 years. There was no significant change

in visual acuity compared with baseline (P = 0.13). 20 (19.0%) patients had one eye with final visual acuity of 20/200 or worse and the leading cause for poor vision was CMV retinitis. 11 selleck compound (10.5%) patients died during the follow-up due to complications of HIV/AIDS. The presence of HIV retinal microangiopathy was significantly associated with mortality (P = 0.005).\n\nConclusions:\n\nCMV retinitis remains the main HIV-related ocular disease in the post-HAART era. HIV retinal microangiopathy might be an important prognostic factor for mortality. Appropriate ophthalmic monitoring is justified to detect for ophthalmic complications in HIV

patients regardless of HAART use in order for prompt initiation of treatment.”
“In this paper, the issue of designing an iterative-detection-and-decoding Selleckchem Birinapant (IDD)-aided receiver, relying on the low-complexity probabilistic data association (PDA) method, is addressed for turbo-coded multiple-input-multiple-output (MIMO) systems using general M-ary modulations. We demonstrate that the classic candidate-search-aided bit-based extrinsic log-likelihood ratio (LLR) calculation method is not applicable to the family of PDA-based detectors. Additionally, we reveal that, in contrast to the interpretation in the existing literature, the output symbol probabilities of existing

PDA algorithms are not the true a posteriori probabilities (APPs) but, rather, MK-8776 clinical trial the normalized symbol likelihoods. Therefore, the classic relationship, where the extrinsic LLRs are given by subtracting the a priori LLRs from the a posteriori LLRs, does not hold for the existing PDA-based detectors. Motivated by these revelations, we conceive a new approximate Bayesian-theorem-based logarithmic-domain PDA (AB-Log-PDA) method and unveil the technique of calculating bit-based extrinsic LLRs for the AB-Log-PDA, which facilitates the employment of the AB-Log-PDA in a simplified IDD receiver structure. Additionally, we demonstrate that we may dispense with inner iterations within the AB-Log-PDA in the context of IDD receivers. Our complexity analysis and numerical results recorded for Nakagami-m fading channels demonstrate that the proposed AB-Log-PDA-based IDD scheme is capable of achieving a performance comparable with that of the optimal maximum a posteriori (MAP)-detector-based IDD receiver, while imposing significantly lower computational complexity in the scenarios considered.

Responsiveness was tested. Changes were analysed using a multistate dynamic model, adjusted for age, gender, ApoE4 genotype and vascular risk factors.\n\nResults Over 2 years, decline in brain structure and

cognition predominated, EX 527 molecular weight each showing detectable effect sizes (Cohen’s d=0.33 for MTAS, 0.32 for BALI, 0.41 for MMSE, 0.38 for ADAS-cog; standard response mean=0.71, 0.69, 0.50 and 0.47, respectively). Structural improvement was observed (10.2% in BALI and 0.8% in MTAS), as was cognitive improvement (23.2% MMSE, 27.2% ADAS-cog). Most people (66.7%) whose BALI score improved also improved in either the MMSE or ADAS-cog. No patient with MCI whose MTAS or BALI improved converted to AD.\n\nConclusions Despite average decline in brain structure, improvement was observed and related to cognition and MCI-AD conversion. Ageing-related brain changes reflect a dynamic process.”
“A 30-year-old male was diagnosed with a disruption of the musculofibrotic abdominal wall as a result of a blunt trauma 3 years after the injury. His traumatic abdominal wall hernia (TAWH) was initially missed on physical examination and GANT61 price computed tomography. The patient presented

now with a lump in the left flank after a period of intended weight loss. Laparoscopic repair of the hernia resulted in being asymptomatic ever since. Missing a TAWH might have major consequences, such as incarceration and strangulation. Therefore, it is important to consider a TAWH after blunt abdominal trauma.”
“The frozen elephant trunk, combining together surgical and endovascular techniques, has been developed to treat patients with extensive disease of the thoracic aorta. In this article, we report three cases in which the frozen elephant trunk could facilitate surgical arch repair and patients’ management. (C) 2011 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.”
“Anthropometric data on the proximal tibia and distal femur of 172

normal knees (94 male knees, 78 female knees) were obtained using three dimensional computer tomographic measurements, We measured the tibial mediolateral (tML) and tibial anteroposterior find more (tAP) dimension in resected proximal tibia surface, femoral mediolateral (fML) and femoral anteroposterior (fAP) dimension in resected distal femur surface. The measurements were compared with the similar dimensions of five total knee prostheses conventionally used in China. We found that in the smaller sized prostheses the tibial mediolateral dimension was undersized, while in the larger size prostheses the tibial mediolateral dimension was overhang. For all sizes of prostheses the femoral mediolateral dimension was overhang.

Collectively, these results indicate that MFG-E8 in a dose-dependent manner coordinates the expression of cell cycle molecules and facilitates VSMC proliferation via integrin/ERK1/2 signaling. Thus, an increase in MFG-E8 signaling is a mechanism of the age-associated increase in aortic VSMC proliferation.”
“A dual navigator-gated, flow-sensitive alternating

inversion recovery (FAIR) true fast imaging CH5183284 with steady precession (True-FISP) sequence has been developed for accurate quantification of renal perfusion. FAIR methods typically overestimate renal perfusion when respiratory motion causes the inversion slice to move away from the imaging slice, which then incorporates unlabeled buy LY2835219 spins from static tissue. To overcome this issue, the dual navigator scheme was introduced to track inversion and imaging slices, and thus to ensure the same position for both slices. Accuracy was further improved by a well-defined bolus

length, which was achieved by a modification version of Q2TIPS (quantitative imaging of perfusion using a single subtraction, second version with interleaved thin-slice TI(1) periodic saturation): a series of saturation pulses was applied to both sides of the imaging slice at a certain time after the inversion. The dual navigator-gated technique was tested in eight volunteers. The measured renal cortex perfusion rates were between 191 and 378 mL/100 g/min in the renal cortex with a mean of 376 mL/100 g/min. The proposed technique may prove most beneficial for noncontrast-based renal perfusion quantification in young children and patients who may have difficulty holding their breath for prolonged periods or are sedated/anesthetized. Magn Reson Med 64:1352-1359, 2010. (C)2010 Wiley-Liss, Inc.”
“Legumes are the third-largest family of angiosperms, the second-most- important crop family, and a key source of biological nitrogen in agriculture. Recently, the genome sequences of Glycine max (soybean), Medicago truncatula, and Lotus japonicus were substantially completed. Comparisons among legume genomes reveal a key role for duplication, especially a whole-genome duplication event approximately

58 Mya that is shared by most agriculturally important AL3818 Protein Tyrosine Kinase inhibitor legumes. A second and more recent genome duplication occurred only in the lineage leading to soybean. Outcomes of genome duplication, including gene fractionation and sub- and neofunctionalization, have played key roles in shaping legume genomes and in the evolution of legume-specific traits. Analysis of legume genome sequences also enables the discovery of legume-specific gene families and provides a framework for genome-wide association mapping that will target phenotypes of special importance in legumes. Translating genomic resources from sequenced species to less studied but still important “orphan” legumes will enhance prospects for world food production.

However, its mechanism had to be clarified.\n\nWe performed re-sequencing and genome-wide variation analysis of 7302R using check details the Solexa sequencing technology. With the genomic sequence of the indica cultivar 9311 as reference, 307 627 SNPs, 57 372 InDels, and 3 096 SVs were identified in the 7302R genome. The 7302R-specific variations were investigated via the synteny analysis of all the SNPs of 7302R with those of the previous sequenced none-IPA-type lines IR24, MH63, and SH527. Moreover, we found 178 168 7302R-specific SNPs across the whole genome and 30 239 SNPs in the predicted mRNA regions,

among which 8 517 were Non-syn CDS. In addition, 263 large-effect SNPs that were expected to affect the integrity of encoded proteins were identified from the 7302R-specific SNPs. SNPs of several important previously

cloned rice genes were also identified by aligning the 7302R sequence with other sequence lines.\n\nOur results provided several candidates account for the IPA phenotype of 7302R. These results therefore lay the groundwork for long-term efforts to uncover important genes and alleles for rice plant architecture signaling pathway construction, also offer useful data resources for future genetic and genomic studies in rice.”
“We explored the perception and receptivity of elderly people regarding the introduction of an intelligent videomonitoring system (IVS) at home. Using a mixed methods design, 25 elderly people with a history of falls completed a structured interview (two questionnaires). In the year preceding the interview, 72% of the participants fell as many as seven times. Open-ended questions (qualitative data) were used to supplement the quantitative data. A content analysis (qualitative data) and a descriptive analysis (quantitative data) were carried out. The participants were 84% favourable or partially favourable https://www.selleckchem.com/products/ly2606368.html to technologies which ensured

home security and 96% favourable or partially favourable to the IVS. About half (48%) said that they would use it. The other participants did not wish to use it unless they had been left to live alone or if their health condition worsened. Thus the living conditions of the elderly appear to influence their perception and receptivity regarding the acceptance and use of an IVS.”
“The manuscript describes the synthesis of novel amide tethered 7-chloroquinoline chalcone and 7-chloroquinoline-ferrocenylchalcone bifunctional hybrids and their evaluation as antimalarial agents against W2 resistant strain of Plasmodium falciparum. The antiplasmodial activity of 7-chloroquinoline-ferrocenylchalcones was found to be less than their corresponding simple chalcone conjugates.

In vitro analysis demonstrated the insect ortholog can bind RNA and hydrolyze the m(7)G cap from the 5′-end of RNAs indicating the Nudt16 gene product is functionally conserved across metazoans. This study also identified a closely related paralogous protein, known as Syndesmos, which resulted from a gene duplication that occurred in the tetrapod lineage near the amniote divergence. While vertebrate Nudt16p is a nuclear RNA decapping protein, Syndesmos is associated HDAC inhibitor with the cytoplasmic membrane in tetrapods.

Syndesmos is inactive for RNA decapping but retains RNA-binding activity. This structure/function analysis demonstrates evolutionary conservation of the ancient Nudt16 protein suggesting the existence and maintenance of a nuclear RNA degradation pathway in metazoans.”
“Background: To elucidate the role of prenatal, neonatal and early postnatal variables in influencing the achievement of full enteral feeding (FEF) in very low birth weight (VLBW) infants and to determine whether neonatal intensive care units (NICUs) differ in this outcome.\n\nMethods: Population-based retrospective cohort CX-6258 inhibitor study using data on 1,864 VLBW infants drawn from the “Emilia-Romagna Perinatal Network” Registry from

2004 to 2009. The outcome of interest was time to FEF achievement. Eleven prenatal, neonatal and early postnatal variables and the study NICUs were selected as potential predictors of time to FEF. Parametric survival analysis was used to model time to FEF as a function of the predictors. Marginal effects were used to obtain adjusted estimates of median time to FEF for specific subgroups of infants.\n\nResults: Lower gestational age, exclusive formula feeding, higher CRIB II score, maternal hypertension, cesarean delivery, SGA

and PDA predicted delayed FEF. NICUs proved to be heterogeneous in terms of FEF achievement. Newborns with PDA had a 4.2 days longer predicted median time to FEF compared to those without PDA; newborns exclusively formula-fed had a 1.4 days longer time to FEF compared to those fed human milk.\n\nConclusions: The results of our study suggest that time to FEF is influenced by clinical variables and NICU-specific practices. Knowledge of the variables associated with delayed/earlier MLN8237 in vitro FEF achievement could help in improving specific aspects of routine clinical management of VLBW infants and to reduce practice variability.”
“Transactive response DNA-binding protein 43 (TDP-43) is a major pathological protein in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). There are many disease-associated mutations in TDP-43, and several cellular and animal models with ectopic overexpression of mutant TDP-43 have been established. Here we sought to study altered molecular events in FTD and ALS by using induced pluripotent stem cell (iPSC) derived patient neurons. We generated multiple iPSC lines from an FTD/ALS patient with the TARDBP A90V mutation and from an unaffected family member who lacked the mutation.

These studies indicate that FGF-23 inhibits phosphate transport in the mouse kidney by processes that involve the scaffold protein NHERF-1. In addition, FGF-23 synergizes with PTH to inhibit phosphate transport by facilitating the activation of the PTH signal transduction pathway.”
“Lipid rafts represent a sub-compartment of the plasma membrane that co-ordinate and regulate varieties LY2606368 in vitro of signalling processes, whereas caveolins are the integral membrane protein of the lipid raft. Recent evidence demonstrated the pivotal role of caveolins in cardioprotection against ischaemic injury, although their mechanism

of action is not clear. However, new understanding of epigenetic modification Navitoclax in vivo during ischaemia reperfusion suggests additional targeted approaches that have not been explored before. To study the role of caveolin on epigenetic regulation, isolated mouse heart was prepared from wild-type (WT) and caveolin-1 knockout (Cav-1 KO) mouse and preconditioned them with four cyclic episodes of ischaemia/reperfusion followed by 30 min. global

ischaemia and 120 min. reperfusion. We found that Cav-1 KO mouse abolished the acetylation of histone (H3 and H4) and increased the methylation of histone in the preconditioned heart. The increased histone methylation was significantly correlated with an increased level of histone methyltranferase G9a protein and increased the level of histone decaetylase (HDAC) activity. Cav-1 KO mouse also decreased the translocation of forkhead transcription factor (FOXO3a) to the nucleus and reduced the induction of the expression of SIRT-1 in the preconditioned heart. Cardioprotective property of Cav-1 was further confirmed by reduced ventricular function, increased cardiomyocyte apoptosis, increased expression of junas kinase (JNK) and Bax and decreased ERK signaling pathway inhibitor expression of phospho-adenosine monophosphate-activated protein kinase (AMPK), phospho-AKT and B cell

lymphoma-2 (Bcl-2) in Cav-1 KO preconditioned heart. The results clearly indicate that Cav-1 induces cardioprotection through epigenetic regulation.”
“This review provides an update of ongoing efforts to expand our understanding of the diversity inherent within the Schistosomatidae, the parasites responsible for causing schistosomiasis and cercarial dermatitis. By revealing more of the species present, particularly among understudied avian schistosomes, we gain increased understanding of patterns of schistosome diversification, and their abilities to colonize new hosts and habitats. Schistosomes reveal a surprising ability to switch into new snail and vertebrate host species, into new intrahost habitats, and may adopt novel body forms in the process. Often these changes are not associated with deep splits or long branches in their phylogeny, suggesting some are of relatively recent origin.