The differences between Paphiopedilum barbatum (Lindl.) and Papiopedilum callosum (Rchb.f.) Stein var. sublaeve (Rchb.f.) P.J. Cribb

The genus Paphiopedilum is a flagship species among orchids and comprises of some of the most sought after orchids for its beauty and rarity. Thus, all Paphiopedilum are placed in CITES Appendix I. Among orchids, Paphiopedilum has the most revised literature. In spite of this, misidentifications tend to occur even in publications. This is mainly due to the close resemblance that some species have with each other. Identification is important for the accurate knowledge on the distribution of the species done through biodiversity inventories as this can result in the decision making of environmental policies and conservation strategies. In the case of P. barbatum and P. callosum var. sublaeve, methods used for the correct species identification include morphological study, distribution and DNA barcoding. The morphology presents many similarities between both species but with some differences in the petal angle, staminode shape and the presence of ciliated hair on the petal margins. Distributions of both species in Peninsular Malaysia do not overlap. DNA barcoding using the molecular markers; rbcL, matK and ITS, were used to differentiate both species. Analysis of sequences generated shows ITS and matK forming two separate clades for each species in Neighbour-Joining trees. The rbcL sequences provided poor species resolution as evidenced from the formation of multiple clades for both species. Presence of barcoding gap and BLAST results were used to confirm the two species. DNA barcoding is an effective taxonomic tool and accuracy is increased when morphology and distribution data are included

Endogenous amyloidogenesis in long-term rat hippocampal cell cultures

<p>Abstract</p> <p>Background</p> <p>Long-term primary neuronal cultures are a useful tool for the investigation of biochemical processes associated with neuronal senescence. Improvements in available technology make it possible to observe maturation of neural cells isolated from different regions of the rodent brain over a prolonged period <it>in vitro</it>. Existing experimental evidence suggests that cellular aging occurs in mature, long-term, primary neuronal cell cultures. However, detailed studies of neuronal development <it>in vitro </it>are needed to demonstrate the validity of long-term cell culture-based models for investigation of the biochemical mechanisms of <it>in vitro </it>neuronal development and senescence.</p> <p>Results</p> <p>In the current study, neuron-enriched hippocampal cell cultures were used to analyze the differentiation and degeneration of hippocampal neurons over a two month time period. The expression of different neuronal and astroglial biomarkers was used to determine the cytochemical characteristics of hippocampal cells in long-term cultures of varying ages. It was observed that the expression of the intermediate filament nestin was absent from cultures older than 21 days in vitro (DIV), and the expression of neuronal or astrocytic markers appeared to replace nestin. Additionally, morphological evaluations of neuronal integrity and Hoescht staining were used to assess the cellular conditions in the process of hippocampal culture development and aging. It was found that there was an increase in endogenous production of Aβ_1-42and an increase in the accumulation of Congo Red-binding amyloidal aggregates associated with the aging of neurons in primary culture. <it>In vitro </it>changes in the morphology of co-existing astrocytes and cell culture age-dependent degeneration of neurodendritic network resemble features of <it>in vivo </it>brain aging at the cellular level.</p> <p>Conclusion</p> <p>In conclusion, this study suggests that long-term primary CNS culture is a viable model for the study of basic mechanisms and effective methods to decelerate the process of neuronal senescence.</p

Pulse radiolysis of liquid water using picosecond electron pulses produced by a table-top terawatt laser system

A laser based electron generator is shown, for the first time, to produce sufficient charge to conduct time resolved investigations of radiation induced chemical events. Electron pulses generated by focussing terawatt laser pulses into a supersonic helium gas jet are used to ionize liquid water. The decay of the hydrated electrons produced by the ionizing electron pulses is monitored with 0.3 μs time resolution. Hydrated electron concentrations as high as 22 μM were generated. The results show that terawatt lasers offer both an alternative to linear accelerators and a means to achieve subpicosecond time resolution for pulse radiolysis studies. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69949/2/RSINAK-71-6-2305-1.pd

Somatotyping of Division I Athletes

Somatotyping has previously examined athletes\u27 genetic morphology. Categorization of somatotyping can be utilized in athletes for specialized, adaptive sports performance. PURPOSE: The purpose of this study was to report somatotyping differences (ectomorph, mesomorph, and endomorph) in selected Division I athletes. METHOD: 39 male football athletes and seven female softball Division I athletes were recruited for this investigation. Height (m), weight (kg), waist-to-hip ratio (cm), and a 4-site skinfold measurement was collected. Skinfold locations were recorded from the triceps (mm), subscapular (mm), supraspinal (mm), and the medial calf (mm). Biepicondylar breadth measures of the humerus (cm), and the femur (cm) were recorded at a respective 90°. Additionally, the girth of the subject’s dominant upper arm (cm) and dominant calf (cm) were recorded. All measurement locations were taken from the Heath-Carter Anthropometric protocol, respectfully. The Heath Carter Somatotype Worksheet consists of a rating scale that is based on a 3-component categorization. All measures are considered when calculating a participant\u27s score. Scores between .5 and 2.5 are low, 3 to 5 are moderate, 5.5 to 7 are high and anything over a 7.5 is considered very high. The first component calculated scores of endomorphy, the second calculated mesomorphy scores, and the last component calculated ectomorph scores. Using these measurements, equations are used to determine a participant’s score to a specific somatotype. The athletes\u27 numbers were then processed and plotted on a 2-D graph plotting the somatotype (X= ectomorph-endomorph, Y=2 x mesomorphy- (endomorphy+ectomorph)). RESULTS: There was a clear indication that somatotyping had variety based on sports and position specialization in football athletes. Football athletes consisted of 6 endomorphs, 30 mesomorphs, and 3 ectomorphs, while softball athletes consisted of 7 meso-endomorphs. CONCLUSION: Due to the anthropometric position differences in male football athletes there was a considerable amount of variety and lack of specificity, while the female softball athletes consisted of a lesser variety in anthropometric measures

DNA barcoding of endangered Paphiopedilum species (Orchidaceae) of Peninsular Malaysia

In this study, the efficacy of four DNA markers and their combinations (rbcL, matK, ITS, trnH-psbA) as barcode markers were tested across the endangered Paphiopedilum species from Peninsular Malaysia. Four species of Paphiopedilum were sampled and barcoded. The DNA barcodes reliabilities were evaluated using NCBI BLASTn program, phylogenetic tree via Neighbour-Joining method with 1000 bootstrap replicates in MEGA 6 and barcoding gap assessment. matK is the most promising barcode with high sequence quality (100%), high accuracy in BLASTn (100%), clear resolution of species in Neighbour-Joining phylogenetic tree (100%) and a distinct barcoding gap followed by ITS, trnH-psbA and rbcL. The combination of barcode regions revealed the lack of variation in rbcL and trnH-psbA but they are still useful for preliminary identification followed up by matK for accurate identification

Accuracy and Performance Comparison of Video Action Recognition Approaches

Over the past few years, there has been significant interest in video action recognition systems and models. However, direct comparison of accuracy and computational performance results remain clouded by differing training environments, hardware specifications, hyperparameters, pipelines, and inference methods. This article provides a direct comparison between fourteen off-the-shelf and state-of-the-art models by ensuring consistency in these training characteristics in order to provide readers with a meaningful comparison across different types of video action recognition algorithms. Accuracy of the models is evaluated using standard Top-1 and Top-5 accuracy metrics in addition to a proposed new accuracy metric. Additionally, we compare computational performance of distributed training from two to sixty-four GPUs on a state-of-the-art HPC system.Comment: Accepted for publication at IEEE HPEC 202

Cytomegalovirus Antigenic Mimicry of Human Alloreactive Peptides: A Potential Trigger for Graft versus Host Disease

The association between human cytomegalovirus (hCMV) reactivation and the development of graft-versus-host-disease (GVHD) has been observed in stem cell transplantation (SCT). Seventy seven SCT donor-recipient pairs (DRP) (HLA matched unrelated donor (MUD), n=50; matched related donor (MRD), n=27) underwent whole exome sequencing to identify single nucleotide polymorphisms (SNPs) generating alloreactive peptide libraries for each DRP (9-mer peptide-HLA complexes); Human CMV CROSS (Cross-Reactive Open Source Sequence) Database was compiled from NCBI; HLA class I binding affinity for each DRPs HLA was calculated by NetMHCpan 2.8 and hCMV- derived 9-mers algorithmically compared to the alloreactive peptide-HLA complex libraries. Short consecutive (6 or greater) amino acid (AA) sequence homology matching hCMV to recipient peptides was considered for HLA-bound-peptide (IC50<500 nM) cross reactivity. Of the 70,686 hCMV 9-mers contained within the hCMV CROSS database, 29,658.8 +/- 9038.5 were found to match MRD DRP alloreactive peptides and 52,910.2 +/- 16121.8 matched MUD DRP peptides (Student's T-test, p<0.001). In silico analysis revealed multiple high affinity, immunogenic CMV-Human peptide matches (IC50<500 nM) expressed in GVHD-affected tissue-specific manner (proteins expressed at 10 RPKM or greater). hCMV+GVHD was found in 18 patients, 13 developing hCMV viremia before GVHD onset with a subset analysis of 7 instances of hCMV viremia prior to acute GVHD onset (n=3), chronic GVHD (n=2) and acute + chronic GVHD (n=2) indicating cross reactive peptide expression within affected organs. We propose that based on our analysis and preliminary clinical correlations that hCMV immune cross-reactivity may cause antigenic mimicry of human alloreactive peptides triggering GVHD.Comment: Pre-submission manuscript, 4 tables, 5 figures, 2 supplements & 2 Appendices-available upon request from first autho

Hormone and Adpokine Alterations across Eleven Weeks of Training in Division I Collegiate Throwers: an Exploratory Study

Conceptually, it is important to understand the underlying physiological mechanisms of any training program model. This understanding aids the coach/sport scientist in making better choices in manipulating variables in formulating the training model. These underlying mechanisms can be associated with training variable manipulation and fatigue management aspects as well as the overall health of the athlete. Hormone and cytokine concentrations can be linked to alterations resulting from the manipulation of training variables and to subsequent alterations in performance (Haff et al., 2008; Ishigaki et al., 2005; Jurimae et al., 2010; Stone et al., 2007). For example, alterations in the testosterone: cortisol ratio (T:C) has been associated with alterations in training volume as well as physiological aspects such as lean body mass (LBM), fat content and strength/power performance (Haff et al., 2008; Häkkinen, 1989; Stone et al., 2007). Although cytokine production is part of the adaptive process, markedly increased/excessive cytokine production has been related poor fatigue management and over training (Angeli et al., 2004; Jurimae et al., 2010; Smith, 2000). The present study followed NCAA division 1 (D-1) collegiate throwers over a period of an 11 week fall semester preparation-phase block form of periodized training. Volume and intensity alterations and their effects on physiological variables (e.g. neuromuscular, hormonal, cytokine) are a key component in understanding the effects of a training process. Alterations in these physiological variables were tracked over time in Division-1 collegiate throwers