Earlier Studies Research Articles

Stable directional sexual selection and repeatable choosiness for song preference in the Pacific field cricket Teleogryllus oceanicus.

Choosiness, or how picky an individual is in mate choice, is key to both sexual selection and speciation. Yet the amount of phenotypic variation in choosiness and how that variation is partitioned among individuals remain largely unexplored. Here, using the Pacific field cricket Teleogryllus oceanicus, we dissect preference for two song traits, proportion of long chirp and interpulse interval. We subsequently quantify phenotypic variation in choosiness and investigate whether there is consistent individual variation in choosiness and whether choosiness for different song traits covary. Strikingly, we found that the overall shape and peak preference for proportion of long chirp remained similar to those reported in an earlier study from the same population more than a decade ago, providing evidence that directional sexual selection can be relatively stable over long time frames in wild populations. Further, we found moderate levels of within-individual repeatability in choosiness for both song traits, suggesting a substantial level of individual variation in choosiness. Interestingly, choosiness for the two song traits positively covaries, indicating that there may exist overall choosier and more permissive females in song preference.

Revision of the Formycin A and Pyrazofurin Biosynthetic Pathways Reveals Specificity for d-Glutamic Acid and a Cryptic N-Acylation Step During Pyrazole Core Formation.

Formycin A and pyrazofurin are two naturally occurring pyrazole-derived C-nucleosides with antibacterial and antiviral activities. While earlier studies have established the chemistry of C-glycosidic bond formation as well as the subsequent steps in the biosynthesis of formycin A and pyrazofurin, how the pyrazole ring itself is constructed remains elusive. While N-N bond formation in the pyrazole ring was previously reported to involve coupling of N6-hydroxylated l-lysine and l-glutamic acid catalyzed by the hydrazine synthetase PyfG, herein PyfG and its homologue ForJ are shown instead to recognize d-glutamate instead of l-glutamate. The hydrazine product of ForJ/PyfG catalysis then releases α-hydrazino d-glutamic acid upon processing by the NAD-dependent oxidoreductase ForL. Furthermore, N-acylation of α-hydrazino d-glutamate with an amino acid catalyzed by the ATP-grasp ligase ForM/PyfJ is indispensable for recognition by the FAD-dependent oxidoreductase ForR/PyfK to perform dehydrogenation of the Cα-N bond and thereby form a hydrazone intermediate. This work not only demonstrates that d-glutamic acid is the correct substrate for hydrazine biosynthesis but also reveals a cryptic N-acylation step in the assembly of the pyrazole core. These results thus provide significant insights into the biosynthesis of pyrazole rings that are rarely seen in natural products.

Precise estimation of elastic modulus of radial artery using blood pressure and vessel wall strain measured by ultrasound and photoplethysmography

Abstract In an earlier study, we investigated methods for estimating the elastic modulus of blood vessel walls for early diagnosis of atherosclerosis. Because the pulse pressure varies from beat to beat, in the present study, we proposed a method for estimating the elastic modulus of the vessel walls that simultaneously measures the pulse pressure and vessel wall strain due to the pulse pressure; this method estimates the systolic and diastolic blood pressures from the vessel diameter and pulse wave velocity. Consequently, changes in vessel wall strain in response to beat-by-beat pulse pressure variation were measured. In the elastic modulus estimation, the maximum deviation among consecutive beats was reduced, and the reproducibility of elastic modulus estimation was improved. Hence, we conclude that simultaneous measurement of vessel wall strain and pulse pressure is effective in improving the reliability of elastic modulus estimation.

Nitrogen concentrations in boreal and temperate tree tissues vary with tree age/size, growth rate, and climate

Abstract. Photosynthesis, growth, and plant maintenance respiration are closely related to tree tissue nitrogen (N) concentrations. While earlier studies of the variation in tissue N concentrations and underlying controls have mostly focused on leaves, here we identify the large-scale controls of N concentration in other tree compartments for the first time. This is achieved by constructing and analysing a novel database of N concentrations in stems, roots, and branches covering all common Northern Hemisphere boreal and temperate tree genera, combined with data for leaves mostly from existing databases. This database allows us to explore the large-scale abiotic (climate, soil N concentration) and biotic controls (tree age/size, leaf type, growth rate) of tree tissue N concentration. We find that N concentrations decrease with increasing tree age (or size) and are significantly higher in deciduous compared to evergreen trees in all tissues. Low growth rates or unfavourable climate conditions (very cold or dry climate) significantly decrease leaf (the latter only for needleleaf deciduous and needleleaf evergreen trees) but not stem N concentration, indicating their effects on N allocation. Plant traits and environmental conditions together explain very large parts of the variation in tissue N concentrations. These results suggest that changes in the distribution of tree age/size, species, and extreme climate, induced by climate change, forest management, or disturbances, will have substantial consequences for the carbon (C) sequestration potential of boreal and temperate forests by altering tissue N concentrations. We expect that the expansion of tree species better adapted to dry conditions in European temperate forests will result in a higher N concentration in all tree tissues and elevated N allocation fractions to stems, which might lead to higher productivity but also higher maintenance respiration. The identified relationships need to be represented in dynamic global vegetation models (DGVMs) to estimate future effects of N limitation on the C cycle.

Network meta-analysis made simple: A composite likelihood approach

Abstract Network meta-analysis (NMA), also known as mixed treatment comparison meta-analysis or multiple treatments meta-analysis, extends conventional pairwise meta-analysis by simultaneously synthesizing multiple interventions in a single integrated analysis. Despite the growing popularity of NMA within comparative effectiveness research, it comes with potential challenges. For example, within-study correlations among treatment comparisons are rarely reported in the published literature. Yet, these correlations are pivotal for valid statistical inference. As demonstrated in earlier studies, ignoring these correlations can inflate mean squared errors of the resulting point estimates and lead to inaccurate standard error estimates. This article introduces a composite likelihood-based approach that ensures accurate statistical inference without requiring knowledge of the within-study correlations. The proposed method is computationally robust and efficient, with substantially reduced computational time compared to the state-of-the-science methods implemented in R packages. The proposed method was evaluated through extensive simulations and applied to two important applications including an NMA comparing interventions for primary open-angle glaucoma, and another comparing treatments for chronic prostatitis and chronic pelvic pain syndrome.

Enterovirus VP1 protein and HLA class I hyperexpression in pancreatic islet cells of organ donors with type 1 diabetes.

Earlier studies of pancreases from donors with type 1 diabetes demonstrated enteroviral capsid protein VP1 in beta cells. In the context of a multidisciplinary approach undertaken by the nPOD-Virus group, we assessed VP1 positivity in pancreas and other tissues (spleen, duodenum and pancreatic lymph nodes) from 188 organ donors, including donors with type 1 diabetes and donors expressing autoantibody risk markers. We also investigated whether VP1 positivity is linked to the hyperexpression of HLA class I (HLA-I) molecules in islet cells. Organ donor tissues were collected by the Network for Pancreatic Organ Donors with Diabetes (nPOD) from donors without diabetes (ND, n=76), donors expressing a single or multiple diabetes-associated autoantibodies (AAb+, n=20; AAb++, n=9) and donors with type 1 diabetes with residual insulin-containing islets (T1D-ICIs, n=41) or only insulin-deficient islets (T1D-IDIs, n=42). VP1 was assessed using immunohistochemistry (IHC) and HLA-I using IHC and immunofluorescence, in two independent laboratories. We determined assay concordance across laboratories and overall occurrence of positive assays, on a case-by-case basis and between donor groups. Islet cell VP1 positivity was detected in most T1D-ICI donors (77.5%) vs only 38.2% of ND donors (p<0.001). VP1 positivity was associated with HLA-I hyperexpression. Of those donors assessed for HLA-I and VP1, 73.7% had both VP1 immunopositivity and HLA-I hyperexpression (p<0.001 vs ND). Moreover, VP1+ cells were detected at higher frequency in donors with HLA-I hyperexpression (p<0.001 vs normal HLA-I). Among VP1+ donors, the proportion with HLA-I hyperexpression was significantly higher in the AAb++ and T1D-ICI groups (94.9%, p<0.001 vs ND); this was not restricted to individuals with recent-onset diabetes. Critically, for all donor groups combined, HLA-I hyperexpression occurred more frequently in VP1+ compared with VP1- donors (45.8% vs 16%, p<0.001). We report the most extensive analysis to date of VP1 and HLA-I in pancreases from donors with preclinical and diagnosed type 1 diabetes. We find an association of VP1 with residual beta cells after diagnosis and demonstrate VP1 positivity during the autoantibody-positive preclinical stage. For the first time, we show that VP1 positivity and HLA-I hyperexpression in islet cells are both present during the preclinical stage. While the study of tissues does not allow us to demonstrate causality, our data support the hypothesis that enterovirus infections may occur throughout the natural history of type 1 diabetes and may be one of multiple mechanisms driving islet cell HLA-I hyperexpression.

Forecasting volatility spillovers across Chinese financial industries: an out-of-sample framework using a novel matrix autoregressive model

ABSTRACT Effective control of current and future financial volatility spillovers is crucial for risk management. Earlier studies indicate the presence of financial volatility spillovers; however, little is known about how to predict their dynamic evolution. This article proposes an out-of-sample forecasting framework based on the novel matrix autoregressive (MAR) model, which fully exploits the predictive information contained in the matrix structure of financial volatility spillovers. Specifically, we estimate cross-industry volatility spillover matrices of Chinese financial institutions by the Elastic Net vector autoregression network approach. We then apply the MAR model to forecast cross-industry volatility spillovers, and further evaluate its predictive ability versus different benchmark models. We find that cross-industry volatility spillovers increase rapidly in response to risk events during the entire period. The banking, insurance, and real estate industries are net volatility receivers, while the securities and diversified financial industries act as net transmitters. Moreover, it is demonstrated that the MAR model outperforms long short-term memory (LSTM) network model, vector autoregressive (VAR) model, and the VAR models with various predictors. The results are robust to a series of tests. Forecasting changes in cross-industry volatility spillovers can provide early warnings for financial regulation and investment decision.

Pastoralism and women’s role in food security in the Ethiopian Somali region

AbstrctPastoralism has a significant role in food security for ages particularly in sub-Saharan Africa, where elevated levels of food insecurity persist. The main aim of this paper is to explore the role of pastoralists and their livestock in enhancing food security in the Somali region of Ethiopia, with a special focus on the contributions of women involved in pastoral activities starting from the fact that their crucial role was often underemphasized in earlier studies. The survey was based on two primary qualitative data collections methods: in depth interviews and focus group. In contrast secondary data were acquired through an insight into literature on the subject. The results from the study have shown a strong relationship between pastoralism and food security in the Somali region highlighting the need to address challenges that limit women’s roles and participation in pastoral activities. The findings of the study have implications for policymakers, development practitioners, pastoral communities and the wider international community. Promoting sustainable livestock farming and enhancing food security in the Somali region of Ethiopia is critical to achieving global food security and sustainable development. The findings also highlighted the need for further research to explore the links between sustainable livestock husbandry, traditional knowledge, and adaptation to climate change in pastoral communities.

Development of a response spectrum model for bifenthrin in juvenile Chinook Salmon (Oncorhynchus tshawytscha).

Development of a response spectrum model for bifenthrin in juvenile Chinook Salmon (Oncorhynchus tshawytscha).

The Sakhalin Ainu: origin and population contacts according to cranial-metric data

The study is focused on recent population history of the Sakhalin Ainu people, which remains rebated over the last 70 years. Albeit it is generally accepted that the Sakhalin Ainu are decedents of Ainu migrants from Hokkaido, significant cranial differences has been revealed between these two related populations. Thus, while M. Levin ar-gued in favor of the Nivkh component in the Sakhalin Ainu population, A. Kozintsev, based on the analysis of cranial non-metric characteristics, assumed the admixture of the Ainu with the Ulchi people, and we in our earlier studies assumed that the Sakhalin Ainu included the descendants of the Okhotsk culture people. The influence of interre-gional contacts between the Sakhalin Ainu and Kuril-Kamchatka populations has not been previously considered. We analyzed individual cranial metric data on the Sakhalin Ainu, the Hokkaido Ainu, and several ancient and histori-cal samples from the Far East region using canonical variate analysis with subsequent clustering of the CVs scores with K-means algorithm. The results revealed high level of morphological diversity of the Sakhalin Ainu sample. The analysis supports that the Sakhalin Ainu are decedents of the Hokkaido Ainu migrants, which admixed with a num-ber of populations of different origin. In addition to the previously assumed Nivkh, Ulch and ancient Okhotsk compo-nents in the Sakhalin Ainu, we assume a rather strong influence of the Itelmens, who, according to the results of our study, may be descendants of the population of the Old Bering Sea culture people.

ChatGPT use in hospitality and tourism: a multi-analytic approach

ABSTRACT This study explored the antecedents of tourists’ intentions to use ChatGPT for seeking information, and investigated the effect of these, using a fuzzy-set approach. The study performed a complex configurational assessment of the technology acceptance model (TAM), the theory of planned behavior (TPB), and behavioral reasoning theory (BRT) to predict tourists’ strong and weak intentions to use AI chatbots for hospitality and tourism information. To attain this research goal, a total of 604 questionnaires were collected using Korean customers who used ChatGPT in Korea. Results of the analyses indicated that multiple factors rooted in the TAM, TPB, and BRT, showed significant interactions resulting in both desirable and undesirable outcomes. Furthermore, the essential role of convenience was found to be one of the BRT factors that increased intentions to use ChatGPT. The present research differs from earlier studies in that it investigated the complex nature of tourists’ behavioral intentions, and therefore the findings advance current knowledge and offer novel insights for practitioners.

Agarwood formed by insect (Neurozerra conferta) infestation involves fungal confection dominated by Neocosmospora solani with enzymatic profiles indicative of the involvement in resin development.

It is believed that the larval stage infestation byNeurozerra confertaWalker ofAquilaria malaccensistrees followed by fungal infections assists in higher-quality agarwood formation. However, it remains unclear what these intricate interactions offer for higher-grade agarwood formation. In the earlier studies, fungal diversity associated with agarwood has been identified and their role in agarwood formation has been fairly well established. However, these studies cover a broad aspect of agarwood fungal diversity and interactions but lack specificity regarding insect infestation, particularly since agarwood can be obtained either naturally through insect-inflicted injuries or artificially induced by different methods. The present study therefore specifically examines the culturable fungal associates in resinous agarwood formed due to the infestation by N. conferta. A total of 12 fungi were isolated belonging to four fungal families, namely Endomelanconiopsidaceae, Hypocreaceae, Nectriaceae, and Trichocomaceae. Internal Transcribed Spacer (ITS) sequencing identified the isolates asEndomelanconiopsis microspore, Fonsecaea monophora, Fusarium incarnatum, Fusarium sp., Neocosmospora solani, Penicillium sp., and Trichoderma cf. harzianum. Screening for enzyme activity revealed the isolates with the highest rate of xylanase activity compared to cellulase and tannase activity. However, most of the fungal isolates could produce the tannase enzyme, implying its potential in overcoming the plant's defense process. N. solaniexhibited abundance and, displayed variations in colony morphology as well as enzyme activities. Therefore, our findings provide a basis for understandingN. solani, as the significant fungal microbe contributing to the agarwood formation via resin development in theN. conferta infestedA. malaccensistrees.

Gamma-aminobutyric acid and glutamate system dysregulation in a small population of Egyptian children with autism spectrum disorder.

Autism spectrum disorder (ASD) is associated with various symptoms, including repetitive behaviors, restricted interests, and deficits in proper communication. Earlier studies have linked these symptoms to abnormalities in the balance between excitatory (glutamatergic signaling) and inhibitory (GABAergic signaling) neurotransmission. The present study aimed to analyze the levels of different biomarkers in children with ASD compared to neurotypical (NT) controls. The study included 80 children, of whom 40 were cases (children with ASD) and 40 were age- and sex-matched NT controls. Serum levels of GABAA, and GABAB receptors, glutamate, zinc, potassium, and calcium were measured in both groups. ASD diagnosis was verified using the Childhood Autism Rating Scale (CARS) and Autism Diagnostic Interview-Revised (ADI-R). There was a significant decrease (P < 0.001) in the median serum levels of GABAA (0.6) and GABAB receptors (2.03) in children with ASD compared to controls. Additionally, a significant increase in median serum glutamate levels was observed in ASD children (102, P < 0.001) compared to controls. Children with ASD also showed a significant reduction (P < 0.001) in median levels of all studied blood minerals compared to controls, including potassium (3.8 vs. 4.6), calcium (9.0 vs. 9.7), and zinc (57.0 vs. 92.0). The roles of GABAB and zinc as potential pathological biomarkers were investigated due to their highly significant inverse correlations with stereotypic and repetitive behaviors (ADI-R domain), with rho = -0.393 (P = 0.012) and rho = -0.488 (P = 0.001), respectively. Further analysis of pathways regulating these biomarkers may provide deeper insights into the etiology and pathophysiology of ASD, paving the way for potential therapeutic interventions.

Highly Optimized Simulation of Atomic Resolution Cell-Like Protein Environment.

Computational approaches can provide details of molecular mechanisms in a crowded environment inside cells. Protein docking predicts stable configurations of molecular complexes, which correspond to deep energy minima. Systematic docking approaches, such as those based on fast Fourier transform (FFT), also map the entire intermolecular energy landscape by determining the position and depth of the full spectrum of the energy minima. Such mapping allows speeding up simulations by precalculating the intermolecular energy values. Our earlier study combined FFT docking with the Monte Carlo protocol, enabling simulation of cell-size, crowded protein systems with seconds, and longer trajectories at atomic resolution, several orders of magnitude longer than those achievable by alternative approaches. In this study, we present a further drastic extension of the modeling capabilities by parallelized implementation of the simulation protocol. The procedure was applied to a panel of Death Fold Domains that form nucleated polymers in human innate immune signaling, recapitulating their homooligomerization tendencies and providing insights into the molecular mechanisms of polymer nucleation. The parallelized protocol allows extension of the simulation trajectories by orders of magnitude beyond the previously reported implementation, reaching into the uncharted territory of atomic resolution simulation of cell-sized systems.

Absolute Quantitative Metagenomic Analysis Provides More Accurate Insights for the Anti-Colitis Effect of Berberine via Modulation of Gut Microbiota

Current gut microbiota studies often rely on relative quantitative sequencing. However, under certain circumstances, while the relative quantitative abundance of these bacteria may remain stable, the absolute quantities of specific bacteria can vary considerably. Since the function of bacteria is directly linked to their total numbers, absolute quantification is crucial. This study aims to identify the optimal method for microbiome analysis by comparing relative and absolute quantitative sequencing. Using ulcerative colitis, which is closely associated with gut microbiota, as a disease model and berberine (which affects microbiota) versus sodium butyrate (which does not) as drugs, relative and absolute quantitative methods were used to evaluate the varying effects of the different drugs on the regulation of gut microbiota in UC-affected animals. The regulatory effects of BBR on gut microbiota were further synthesized as identified in earlier studies using an individual-based meta-analysis, and we compared these findings with our absolute sequencing results. The results from absolute sequencing were more consistent with the actual microbial community, suggesting that relative abundance measurements might not accurately reflect the true abundance of microbial species. Moreover, meta-analysis results were only partially consistent with absolute quantitative sequencing and sometimes directly opposed, suggesting that relative quantitative sequencing analyses are prone to misinterpretation and incorrect correlation of results. This study underscores the importance of absolute quantitative analysis in accurately representing the true microbial counts in a sample and evaluating the modulatory effects of drugs on the microbiome, which plays a vital role in the study of the microbiome.

Identification and characterization of the elusive protein backbone of the immuno-dominant and species-specific Em2(G11) metacestode antigen of Echinococcus multilocularis

Alveolar echinococcosis (AE) caused by Echinococcus multilocularis, is a severe zoonotic disease in humans. One of the major metacestode antigens of E. multilocularis is the Em2 or Em2(G11) native purified antigen. The Em2 antigen is used for the serological and histopathological diagnosis of AE in humans and plays an important role in parasite–host interactions. As the Em2(G11) antigen is a mucin-type and glycosylated protein, the protein backbone has not been identified yet. We have targeted the protein backbone identification through mass spectrometry (LC-MS/MS) analysis of the Em2(G11) antigen. As a result, we evidenced that the Em2(G11) antigen consists of 33 unique protein candidates of which the most abundant was ‘’EmuJ_001105600.1’’. This protein (889 amino acids) had 427 predicted glycosylation sites. Amino acid composition comparison was in agreement with earlier studies and further confirmed the candidate of interest as the most likely Em2(G11) protein backbone. NCBI BLAST revealed no other known protein homologues in related Echinococcus species nor helminths. After successfully producing this protein recombinantly (Em2rec), a monoclonal antibody (mAbEm2rec) was raised against it. Immunohistochemical stainings of liver tissue sections of AE patients showed that the mAbEm2rec reacts specifically with E. multilocularis antigens solely after deglycosylation with an O-glycosidase cocktail. Similarly, in ELISA, the mAbEm2rec recognized the recombinant and native antigens of E. multilocularis after deglycosylation. These results reveal the nature of this highly glycosylated and specific protein, where mucins are covering the proteomic backbone. For antibody detection in human patients, the native Em2(G11) antigen was superior compared to the Em2rec antigen, indicating the importance of glycosylated epitopes in this immuno-dominant antigen. Of note is the second most abundant protein in the Em2(G11) antigen, namely phosphoenolpyruvate carboxykinase (PEPCK; EmuJ_000292700.1). PEPCK is known to play an important part in the metabolic pathway of gluconeogenesis in E. multilocularis. However, whether this co-eluted protein has any functional importance in the parasite-host interplay of nutrients, growth, and diagnostic significance, is not explored. By combining various approaches, we were able to uncover and confirm the protein backbone of the diagnostic Em2(G11) antigen of E. multilocularis.

Day-to-day blood pressure variability and cognitive function in the elderly with acute heart failure.

Heart failure (HF) and cognitive impairment often occur together in older adults. Although earlier studies have reported an association between blood pressure (BP) variability (BPV) and cognitive impairment, the underlying pathophysiology remains unclear in HF. In this study, the hypothesis that higher BPV is associated with cognitive impairment was evaluated in the elderly patients with acute decompensated HF (ADHF). Day-to-day in-hospital BPV and cognitive function using a mini-mental state examination (MMSE) were assessed in 245 elderly patients (82.9 ± 6.0 years, 49.4% male) with ADHF. Based on the data of 7 days, day-to-day BPV (expressed as the standard deviation [SD], coefficient of variation [CV], maximum BP, minimum BP, and δ [maximum-minimum] BP) were measured. According to MMSE score quartiles, significant differences were observed in SD (8.2 vs 6.2 vs 6.7 mmHg, p<0.001), CV (13.3 vs 9.94 vs 10.9 %, p<0.001) and δ (22.8 vs 17.5 vs 18.6 mmHg, p<0.001) in diastolic blood pressure (DBP) between three groups. In the logistic regression analysis adjusted for the confounders, SD (OR: 1.23, p<0.01), CV (OR: 1.12, p<0.01), maximum (OR: 1.13, p<0.001) and δ (OR: 1.07, p<0.01) in DBP were significantly associated with the lowest quartile of MMSE score. In the stratified analysis by HF phenotypes, significant associations of day-to-day DBP variability were found with the lowest quartile of MMSE score specifically in the HF with preserved ejection fraction group (HFpEF). Cognitive impairment in association with day-to-day BPV is increasingly prevalent in elderly patients presenting with ADHF, specifically in HFpEF.

Investigating the design-science connection in a multiweek engineering design-based introductory physics laboratory task

Reform documents advocate for innovative pedagogical strategies to enhance student learning. A key innovation is the integration of science and engineering practices through engineering design (ED)-based physics laboratory tasks, where students tackle engineering design problems by applying physics principles. While this approach has its benefits, research shows that students do not always effectively apply scientific concepts, but instead rely on trial-and-error approaches, and end up their way to a solution. This leads to what is commonly referred to as the —that students do not always consciously apply science concepts while solving a design problem. However, as obvious as the notion of a may appear, there seems to exist no consensus on the definitions of and , further complicating the understanding of this gap. This qualitative study addresses the notion of the design-science gap by examining student groups’ discussions and written lab reports from a multiweek ED-based undergraduate introductory physics laboratory task. Building on our earlier studies, we developed and employed a nuanced, multilayered coding scheme inspired by the Gioia Framework to characterize and . We discuss how student groups engage in various aspects of design and how they apply physics concepts and principles to solve the problem. In the process, we demonstrate the interconnectedness of students’ design thinking and science thinking. We advocate for the usage of the term as opposed to to deepen both design and science thinking. Our findings offer valuable insights for educators in design-based science education. Published by the American Physical Society 2025

Chromosome numbers of miscellaneous southwestern North American angiosperms

Fifty-nine original meiotic chromosome counts are presented for 43 angiosperm species across 31 genera in 14 families. Reports are based on observation of pollen mother cells in flower bud collections made from wild populations in New Mexico, western Texas, southeastern Arizona, and north-central Mexico. Of these 59 counts, 10 are first reports, nine belong to assorted genera of Nyctaginaceae (Acleisanthes, Allionia, Boerhavia, Cyphomeris, Mirabilis) and one pertains to Lamiaceae (Scutellaria). New counts and results are compared to chromosome counts and analyses published in earlier studies. Findings highlight specific taxa, populations and areas that would benefit from additional sampling to elucidate patterns of variation related to cytology and biodiversity that could, in turn, strengthen genomic studies, taxonomic classifications and conservation strategies.

Combustion-derived carbon nanoparticles cause delayed apoptosis in neutrophil-like HL-60 cells in vitro and in primed human neutrophilic granulocytes ex vivo

BackgroundInhalation of combustion-derived nanoparticles may contribute to the development or exacerbation of inflammatory lung diseases by direct interaction with neutrophilic granulocytes. Earlier studies have shown that exposure of human neutrophils to carbon nanoparticles ex vivo causes a prolongation of cellular life by the reduction of apoptosis rates. Accordingly, reduced neutrophil apoptosis rates were observed in neutrophils from bronchoalveolar lavages from carbon nanoparticle-exposed animals. The current study describes molecular and cellular modes of action responsible for this proinflammatory effect.ResultsExperiments with human blood neutrophils or neutrophil-like differentiated HL-60 cells exposed to carbon nanoparticles revealed dose dependent reduction of apoptosis rates. In both experimental systems, intracellular reactive oxygen species proved to be causally linked to this endpoint. Among the human samples, only primed cells from donors with slightly elevated proinflammatory plasma factors responded by delayed apoptosis. These neutrophils are characterized by an immunophenotype (CD16bright CD62Ldim) which is also observed in inflammatory lung diseases. Upon exposure to carbon nanoparticles these cells are further activated in an oxidant dependent manner. This activation appears to be linked to reduced apoptosis as samples with unchanged apoptosis rates were also not responding at this level. As reactive oxygen species triggered by carbon nanoparticles are known to cause membrane rearrangements, lipid raft structures were investigated by ganglioside M1 staining. Exposure of neutrophils resulted in a reduction of raft structures which could be prevented by an antioxidant strategy. The destruction of lipid rafts by depleting cholesterol also caused an activated immunophenotype and delayed apoptosis, indicating that membrane rearrangements after carbon nanoparticle exposure in primed neutrophils are responsible for cell activation and delayed apoptosis.ConclusionsThe antiapoptotic reactions observed in two independent experimental systems, differentiated neutrophil-like HL-60 cells and primed neutrophils, may be considered as additional proinflammatory effect of inhaled combustion-derived nanoparticles. Particularly in chronic diseases, which are characterized by neutrophilic lung inflammation, this effect can be expected to contribute to the deterioration of the health status. The data describe a mode of action in which intracellular reactive oxygen species cause membrane rearrangements that are responsible for neutrophil activation and delayed apoptosis.