Heterogeneity Hypothesis Research Articles

Sea lamprey nests promote the diversity of benthic macroinvertebrate assemblages.

The habitat heterogeneity hypothesis states that increased habitat heterogeneity promotes species diversity through increased availability of ecological niches. We aimed at describing the local-scale (i.e. nest and adjacent substrate) effects of nests of the sea lamprey (Petromyzon marinus L.) as ecosystem engineer on macroinvertebrate assemblages. We hypothesized that increased streambed physical heterogeneity caused by sea lamprey spawning would modify invertebrate assemblages and specific biologic traits and promote reach-scale diversity. We sampled thirty lamprey nests of the Nive River, a river of the south western France with a length of 79.3 km and tributary of the Adour River, in three zones: the unmodified riverbed (upstream) and zones corresponding to the nest: the area excavated (pit) and the downstream accumulation of pebbles and cobbles (mound). The increased habitat heterogeneity created by lamprey was accompanied by biological heterogeneity with a reduced density of invertebrates (3777 ± 1332 individuals per m2 in upstream, 2649 ± 1386 individuals per m2 in pit and 3833 ± 1052 individuals per m2 in mound) and number of taxa (23.5 ± 3.9 taxa for upstream, 18.6 ± 3.9 taxa in pit and 21.2 ± 4.5 taxa for mound) in the pit compared to other zones. However the overall taxa diversity in nest increased with 82 ± 14 taxa compared to the 69 ± 8 taxa estimated in upstream zone. Diversity indices were consistent with the previous results indicating a loss of α diversity in pit but a higher β diversity between a pit and a mound than between two upstream zones, especially considering Morisita index accounting for taxa abundance. Trait analysis showed high functional diversity within zones with a reduced proportion of collectors, scrapers, shredders, litter/mud preference and small invertebrates in mound, while the proportion of "slabs, blocks, stones and pebbles" preference and largest invertebrates increased. Pit presented the opposite trend, while upstream had globally intermediate trait proportions. Our results highlight important effects on species and functional diversity due to habitat heterogeneity created by a nest-building species, what can ultimately influence food webs and nutrient processes in river ecosystems.

Sarcosaprophagous flesh flies (Diptera: Sarcophagidae) are less diverse in Amazon Forest than mangroves in Northeast Brazil: preliminary insights about environmental heterogeneity

ABSTRACT Environmental heterogeneity can affect the diversity of arthropods, resulting in a positive relationship in most studies, including of some Diptera groups. We investigated the diversity patterns of Sarcophagidae fauna in two phytophysiognomies with inferences about the environmental heterogeneity. In our hypothesis, the flesh flies have higher diversity in more heterogeneous environments than in the more homogeneous one. The study was performed in São Luís Island, state of Maranhão, Northeast Brazil. In total, we found 1482 specimens, of which 402 were males, representing six genera and 26 species. Peckia (Euboettcheria) collusor (Curran and Walley) was the most abundant species. The mangrove community was more diverse than the forest community. Species replacement contributes more significantly to the difference in species composition between environments than richness difference does, with higher values of dissimilarity of taxonomic diversity. Our data show that sarcosaprophagous flesh flies have a preference for open and sunny environments, implying greater diversity in mangroves rather than in forested areas. The negative relationship between species richness/abundance and vegetation cover in our study corroborates flesh flies’ preference for open environments. Our data show a tendency to refute the environmental heterogeneity hypothesis. The mangrove fauna, especially Diptera communities, has received less attention. Nevertheless, mangrove has the potential to shelter high species richness, highlighting the need for further studies and conservation plans for these areas.

Exploring Heterogeneous Structural Relationships Between E-Shopping, Local Accessibility, and Car-Based Travel: An Application of Enriched National Household Travel Survey Add-on Data

This study analyzes structural relationships between information and communication technology (ICT), e-shopping, local accessibility, and travel intensity in the U.S. state of Georgia. Beginning with the 2017 National Household Travel Survey (NHTS), we enriched the data by exploiting the add-on program. After obtaining contact information for the Georgia NHTS participants who expressed willingness to take a follow-up survey, we conducted another survey with those participants. In addition, we appended land use characteristics associated with respondents’ home locations. To test the hypothesis of possible heterogeneity in structural relationships, we applied a mixed structural equation model. We corroborated our hypotheses that the use of ICT has a positive impact on e-shopping frequency, whereas local accessibility reduces e-shopping frequency. In addition, we identified two meaningful segments exhibiting different structural relationships. The smaller segment (12.7%) showed complementary effects of e-shopping on car-based travel intensity, but local accessibility did not have a significant impact on car-based travel intensity. The dominant segment (87.3%) presented a negative impact of local accessibility but no meaningful effect of e-shopping frequency on car-based travel intensity. A post-hoc analysis revealed meaningful differences in demographics between the two classes. The study suggests that an assumption of homogeneous structural relationships between e-shopping and car-based travel intensity and between local accessibility and car-based travel intensity may not hold. The paper discusses benefits and practical issues concerning fusion of the NHTS data with other data sources. In addition, it stresses the potential of the NHTS add-on program and notes some recommendations.

Concepts and cognitive structures

ABSTRACT The broad topic of this paper is the relationship between the theoretical notion of a concept and familiar types of cognitive structures (prototypes, exemplars, causal models, etc.) The discussion is organized around different ways that theorists about concepts can attempt to accommodate what has been dubbed the Heterogeneity Hypothesis (roughly: the claim that various types of structures with which concepts have been identified co-exist and form a heterogeneous class). The most general goal of the paper is to clarify the dialectical geography when it comes to different ways of construing the relationship between concepts and familiar cognitive structures. A more focussed and more polemical goal of the paper is to raise problems for so-called pluralist approaches to concepts. This paper will not offer a comprehensive defense of any particular view about the relationship between concepts and cognitive structures, but the discussion will be a convenient venue in which to highlight some virtues of what I will call Higher-Level Unity approaches to concepts.

Heterogeneous debt financing and environmental research & development: Evidence from China

This study investigates the relationship between heterogeneous debt financing and environmental research and development (R&D) based on debt heterogeneity hypothesis using Chinese listed firms from 2011 to 2019. Results show that firms with higher trade credit are more likely to engage in environmental R&D, while firms with more bank credit unlikely conduct environmental R&D. Bank credit restrains firms' environmental R&D through aggravating its financing constraints, and trade credit stimulates firms' environmental R&D by increasing its excess cash holdings. Considering firms heterogeneity, the negative effect of state-owned firms' bank credit on environmental R&D is more pronounced than that of non-state-owned firms. In contrast, trade credit's positive impact on environmental R&D only exists in state-owned firms. Further researches suggest that the Environment Protection Law promotes firms to engage in environmental R&D, but it only weakens the relationship between bank credit and environmental R&D. The study reveals that heterogeneous debt financing can exert different effects on environmental R&D, which expands theoretical connotation of the debt heterogeneity hypothesis, and enriches the literature on environmental R&D.

I-divergence based statistical inference for heteroscedasticity and compounds of arsenic contamination in Chile

Arsenic and arsenic compounds contamination is at present a topic of great importance in the field of water quality. Simply applying ANOVAs to test the hypothesis of mean heterogeneity of arsenic contamination in water may lead to oversimplifications, since data can be skewed and the power of many tests will be affected by this skewness. In order to overcome such a problem, we introduce a novel heterogeneity measure of arsenic contamination. This measure is based on the correlation between two univariate statistics decomposed from the Kullback-Leibler divergence of sampled vector as compared to the canonical parameter. For the Gamma distribution, the mere detection of heterogeneity in the means or variances is akin to an omnibus test for mean differences in a standard ANOVA, so our method is useful in this regard. We illustrate this measure's applicability and usefulness in assessment of pollutant compounds. Subsampling and resampling algorithms are developed in order to facilitate a study in a one sample setting. The method is applied to a heteroscedasticity assessment of the arsenic contamination of potable water from the rural area of the region of Arica and Parinacota, Chile.

Analysis of predictors of response to anti-IgE therapy in patients with severe atopic bronchial asthma in real clinical practice

Guidelines on Biological Therapy for Bronchial Asthma of the European Academy of Allergy and Clinical Immunology (EAACI) identified a number of controversial issues for additional outcome analysis using randomized clinical trials and data from routine clinical practice. In particular, there is unmet need to clarify algorithms for prescribing biologicals using predictors of response and its timing, taking into account risk factors and multimorbidity. Omalizumab is a recombinant humanized monoclonal anti-IgE antibody of IgG1 class used for the treatment of severe refractory atopic bronchial asthma (BA) and a variety of IgE-mediated diseases. Among biological agents, this "pioneer molecule" has the greatest experience in the "allergology and immunology" profile. Detailed description of the "nonresponders" portraits will allow to perform the therapy response assessment on time and facilitate rational planning of individual therapy, which is a prerequisite for biologicals era. Using only routine methods, it is possible to perform initial and dynamic screening to phenotype a heterogeneous cohort of patients with severe asthma and chose the optimal strategy. To identify predictors of nonresponse to omalizumab anti-IgE therapy in patients with severe atopic BA and to establish optimal timing of efficacy assessment using retrospective analysis of data from the Biologic Therapy Registry of Allergology and Immunology in routine clinical practice. A retrospective single-center registry study was conducted at the Allergy and Immunology Reference Center from June 2017 to August 2021. 135 patients with severe BA, with confirmed perennial sensitization, who received omalizumab according to the recommendations of the current version of GINA, were selected from the clinical and dynamic observational system (registry). Dosing regimen and administration frequency of omalizumab were determined in accordance with the instructions for the drug. Assessment of therapy efficacy was performed at the time point 4, 6 and 12 months. Patients were subgrouped into "responders" and "non-responders" according to the following criteria: ACT score less than 19 and/or difference between initial ACT score in dynamics less than 3 points; forced expiratory volume in the first second less than 80%; combination of these two criteria. Nonparametric methods of descriptive statistics were used in data processing: median, interquartile range. Differences were considered significant at p0.05. MannWhitney U-test, KruskalWallis one-way analysis of variance, and Fisher's 2 test were used to compare quantitative characteristics. Heterogeneous subgroups of patients differing in reaching the criteria of "non-responders" to treatment were identified; the informativity of modifiable and unmodifiable factors differed at time-points of dynamic observation. In the differential analysis, two profiles of "nonresponders" were defined in combination with the most significant predictors of "nonrsponse" to omalizumab. According to the data obtained, one of the clinical phenotypes, namely the combination of severe asthma with the Samters triad, corresponded to the characteristics of the patient "nonresponders": age of onset is about 30 years, females, severe exacerbations of BA while taking non-steroidal anti-inflammatory drugs, accompanied with high levels of eosinophilia. The data obtained illustrates the hypothesis of pathogenetic heterogeneity of severe BA with the phenomenon of overlapping phenotypes and can serve as an additional orienteer for creating the individual plan of anti-IgE therapy in real clinical practice.

Management diversity begets biodiversity in production forest landscapes

How to manage forest for biodiversity conservation is an ongoing debate. We argue that maximizing biodiversity in managed forest landscapes requires a diversity of forest management regimes in space and time. This will generate high levels of habitat heterogeneity at a landscape scale, which in turn will support various groups of forest species. Based on concepts from landscape ecology, we formulate five hypotheses on how management diversity, i.e. combining various management approaches can benefit overall biodiversity across a production forest landscape. First, management diversity will increase habitat diversity and, therefore, beta diversity (the habitat diversity hypothesis). Second, asynchrony in management timing will enhance long-term availability of different habitat types (the spatio-temporal heterogeneity hypothesis). Third, management to create spatial adjacency or proximity of stands with different management or successional stages will increase biodiversity by providing simultaneous access to multiple resources (the interspersion hypothesis). Fourth, heterogeneous unmanaged set-aside forests, interspersed with managed forests, are needed for complete biodiversity conservation (the natural forest hypothesis). Fifth, management diversity will create functional landscape connectivity between protected forests for multiple species through time (the temporary corridor hypothesis). Although strongly grounded in landscape and forest ecology, these five hypotheses remain largely under-investigated, and we suggest methods for how they can be tested. In the meantime, we suggest that increasing forest management diversity represents a risk-spreading approach for adaptation to global change, and therefore is likely a reasonable objective for sustainable forestry moving forward.

Terrestrial Ant Assemblages (Hymenoptera: Formicidae) in Protected Forests and Grasslands in Three Ecoregions of Corrientes Province, Argentina.

A comparative study on forests and grasslands in three ecoregions (Humid Chaco, Espinal, and Paranaense) was conducted in two protected areas in northeastern Argentina: Iberá National Park and Mburucuyá National Park. The effects of habitat heterogeneity (vegetation cover) on terrestrial ant (Formicidae) assemblages were analyzed and compared. The habitat heterogeneity hypothesis-which predicts that when environmental structural complexity increases, the species richness will also increase-was tested. Two sites were selected in each ecoregion. A forest and a grassland were surveyed in each site, using unbaited pitfall traps from October 2013 to February 2014. Overall, 5,465 ants belonging to 37 species were collected, 32 of which were present in forests and 26 in grasslands. Solenopsis invicta Buren (Hymenoptera: Formicidae) and Pheidole radoszkowskii Mayr (Hymenoptera: Formicidae) were the most abundant species. Formicidae assemblages were compared in terms of abundance, species richness, and diversity between habitats and ecoregions. The results of this study support the habitat heterogeneity hypothesis, since we found a higher diversity of ants in more structured habitats (i.e., forest) in the three ecoregions analyzed. Also, the ant assemblages differed both between habitats and between ecoregions. Our findings provide the first assessment of terrestrial ant assemblages in natural habitats of the three ecoregions in Corrientes Province, Argentina.

Surface reflectance and pXRF for assessing soil weathering indexes

The use of satellite images is a widespread technique for estimating soil attributes. However, what is the potential of satellite data on the prediction of soil weathering indices? How much in their performance is affected by spectral mixing and data resolution? There is no consensus for answering these questions. Hence, the main objectives of this work were: i) to show the difference of spectral signature between prepared and field-condition samples; ii) to compare the convoluted data from laboratory spectroradiometer with the spectral signatures from Sentinel-2 and Landsat-8 satellites; and iii) to build and evaluate predictive models for soil weathering indices using diffuse reflectance spectroscopy from samples under natural conditions, air-dried-sieved and from satellite images. Soil samples were collected from the first 1-cm depth in 27 locations along seven catenas located in a 163-ha area in São Paulo State, Brazil. The samples were analyzed by a Vis-NIR-SWIR spectrometer without sample preparation (field conditions) and after being air-dried and sieved (prepared). The air-dried-sieved samples were also analyzed by an X-ray fluorescence equipment. Reflectance data were obtained from Sentinel and Landsat for the same 27 locations. The spectral data from the lab were convoluted to respective bands of the real satellite data. Predictive models for soil weathering indices using the convoluted laboratory data and the satellite data were also built and compared. The reflectance of samples under field conditions contrasted significantly between soils derived from basalt and sedimentary rocks. In general, the reflectance intensity of prepared samples was 80% higher than that observed for field-conditions, which can be explained by the roughness and the structure effect. However, some cases showed an opposite trend, with a smaller relative reflectance from the air-dried-sieved samples. These trends support the hypothesis of aggregates heterogeneity and clay occlusion. The sample preparation can increase or decrease the reflectance of the soil surface material, depending, mainly, on roughness, soil structure and particles occlusion by the structure. The Landsat spectral signatures were more similar to those from convoluted laboratory than to the Sentinel ones. The satellite performance on the estimation of the soil weathering indices is comparable to those from convoluted laboratory data, but it is limited by spectral resolution. Sentinel and Landsat achieved ratio of performance to interquartile distance (RPIQ) from 1.53 to 2.38 and from 1.56 to 2.42 on soil weathering indices estimation, respectively. The models for Plagioclase Index of Alteration (PIA) and Si/Ti [Si and (Ti and Al) ratio] indices were considered the best ones (RPIQ from 2.17 to 3.6; and RPIQ from 1.90 to 5.56; respectively) for both laboratory and satellite data; in turn, Si/Al, Si (Al + Fe) and Chemical Index of Alteration (CIA) indices performed poorly/reasonably (RPIQ <1.92).

Effects of environmental changes on interspecific interactions of three sympatric pheasants – A study based on long-term monitoring data

• Interactions of 3 pheasants were studied using a new model based on long-term data. • And considered habitat filtering and indirect species interactions together. • Both positive and negative interactions existed among 3 pheasants. • Species interactions varied with habitat heterogeneity and stress levels in 11 years. As the lack of a general understanding of how interspecific interactions change along varying environmental gradients exists, predicting the response of ecological communities to habitat and climate change becomes an arduous task. Researchers generally assess interspecific interactions by investigating species co-occurrence patterns. However, habitat filtering and indirect interspecific interactions can interfere with interspecific interaction signals in co-occurrence data, and these two factors have rarely been considered jointly in previous studies. By using the Markov random fields model which can control the indirect interaction, based on the 11-year co-occurrence data, we analyzed the effects of environmental factors on the interaction of three sympatric pheasant species (Chinese Bamboo Partridge Bambusicola thoracicus , Sichuan Hill Partridge Arborophila rufipectu , Temminck's Tragopan Tragopan temminckii ) in Laojunshan National Nature Reserve, China. To eliminate the interference of habitat filtering, we took the environmental change during the 11-year period as the environmental variable instead of the environmental spatial gradient commonly used in previous studies. We found that the positive interaction increased with the increase of temperature, and decreased with the increase of precipitation, and with the increase of EVI heterogeneity, the positive interaction increased and the negative interaction decreased. The results are consistent with the predictions of habitat heterogeneity hypothesis and stress gradient hypothesis. Our study provides an idea for the follow-up studies of how to eliminate the interference of habitat filtering and indirect interaction in interspecific interaction analysis.

中国蔷薇属植物物种丰富度分布格局及其与环境因子的关系

物种丰富度的大尺度地理格局及其成因是宏观生态学及生物地理学的中心议题之一。蔷薇属（Rosa L.）植物具有很高的经济价值和生态价值，探讨中国蔷薇属植物的丰富度分布格局及其影响因素可为该属植物资源的保护和合理开发利用乃至其系统进化研究提供重要依据。基于蔷薇属植物在中国的15451条分布数据和11种地理、气候等环境因子进行了物种丰富度分析和相关性分析，研究结果显示：（1）蔷薇属植物在中国分布不均匀。在水平方向上，蔷薇属植物于26.19°-34.29°N带内有较高的物种丰富度，之后随着纬度的增加而降低，且随着经度的增加表现为先增加后减少，于99.10°-108.47°E间存在明显的峰值；在垂直方向上，蔷薇属植物的物种丰富度随海拔的增加表现为先增加后减少，956.46-3518.60m范围内的丰富度最高。西南横断山区为蔷薇属物种分布的中心地区，新疆北部及东北长白山周边地区为局部聚集区。（2）蔷薇属物种丰富度与各能量、水分和生境异质性因子均呈正相关关系，与气候稳定性因子呈负相关关系。表明中国蔷薇属植物在水分和热量条件好、气候季节性变化小且生境异质性程度高的地方，有着更高的物种丰富度。（3）蔷薇属植物丰富度与各因子的关系基本支持了生产力假说、环境稳定性假说和生境异质性假说。但蔷薇属的物种丰富度格局并非完全由这些假说解释，历史环境、地形、土壤、人类活动等其他因子可能也有一定的影响作用。（4）水分因子的单独解释率占34.6%（R²；P<0.001），是影响蔷薇属物种丰富度格局的主导因子，这可能是由该类群的进化历史、生理适应等原因共同决定的。本研究可以为蔷薇属植物的分类、进化、以及野生资源的保护和开发利用提供参考。;Understanding macro-scale spatial patterns in species richness and their underlying mechanisms is an important issue to macroecology and biogeography. Rosa species have a high economic and ecological value. Exploring the geographic patterns of species richness and their environmental determinants of Rosa in China will facilitate the resources protection and rational utilization, as well as systematic and evolutionary research of the genus. In this study, datasets of 15451 distributional records and 11 environmental factors were used to conduct species richness and correlation analyses. The results show that (1) Rosa is unevenly distributed in China. The species richness is the highest at latitudes ranging from 26.19°N to 34.29°N, and decreases as the latitude increase. The richness of Rosa is the highest at longitudes ranging from 99.10°E to 108.47°E, and decreased from this optimal range to the west and the east. The species richness shows unimodal pattern that increases first and then decreases with the increase of altitude, with the maximum value between 956.46 m and 3518.60 m. The central aggregation areas are located in the mountain areas around Sichuan Basin as well as Hengduan Mountains, and Chang Bai Mountains region and northern Xinjiang are the local aggregation areas. (2) The energy, water and habitat heterogeneity are positively associated with species richness. In addition, there are negative correlations between species richness and environmental stability. The Rosa has higher species richness in regions with the suitable hydrothermal conditions, the steady climate, and the great habitat heterogeneity. (3) The relationship between the species richness and the environment factors basically supports the productivity hypothesis, the environmental stability hypothesis and the habitat heterogeneity hypothesis. However, the hypotheses cannot fully explain the species richness pattern of Rosa, which indicates that other factors such as historical environment, terrain, soil properties or human activity probably have played a role in shaping the richness pattern of Rosa species. (4) Water factors account for 34.6% (P<0.001) of the species richness patterns of Rosa, so water is the dominant factor, which might be determined by the evolutionary history, physiological adaptation and other reasons. Our results can provide valuable information for the classification, evolution, protection and exploitation of wild resources of the Rosa species.

Protective Effects of Familial Longevity Decrease With Age and Become Negligible for Centenarians.

It is known that biological relatives of long-lived individuals demonstrate lower mortality and longer life span compared to relatives of shorter-lived individuals, and at least part of this advantage is likely to be genetic. Less information, however, is available about effects of familial longevity on age-specific mortality trajectories. We compared mortality patterns after age 50 years for 10 045 siblings of US centenarians and 12 308 siblings of shorter-lived individuals (died at age 65 years). Similar comparisons were made for sons and daughters of longer-lived parents (both parents lived 80 years and more) and shorter-lived parents (both parents lived less than 80 years) within each group of siblings. Although relatives of longer-lived individuals have lower mortality at younger ages compared to relatives of shorter-lived individuals, this mortality advantage practically disappears by age 100 years. To validate this observation further, we analyzed the survival of 3 408 US centenarians born in 1890-1897 with known information on maternal and paternal life span. We found using the Cox proportional hazards model that both maternal and paternal longevity (life span 80+ years) is not significantly associated with survival after age 100 years. The results are compatible with the predictions of reliability theory of aging suggesting higher initial levels of system redundancy (reserves) in individuals with protective familial/genetic background and hence lower initial mortality. Heterogeneity hypothesis is another possible explanation for the observed phenomena.

Unveiling route choice strategy heterogeneity from smart card data in a large-scale public transport network

We contribute to the understanding of public transport passenger route choice behavior by developing and applying methods that capture behavioral strategies by making use of smart card data. We begin by proposing the classification of possible route choice behavioral strategies in two groups: disaggregated strategies and aggregated strategies. In the former, the alternatives correspond to itineraries, which are fixed sequences of stops and public transport lines. In the latter, common line alternatives are considered, which are combinations of itineraries defined under given criteria. Almost all route choice models use consideration sets composed only of itineraries, while public transport assignment models for strategic analysis mostly use a version of the common lines approach. We postulate that this dichotomy is inappropriate and that, instead, heterogeneity exists in the route choice strategy, both between users and across contexts. With the aim of verifying this hypothesis, we first propose an indicator function constructed as the difference between expected and observed trips for a given behavioral assumption. We apply then the indicator to a case study based on smart card data from the city of Santiago, Chile, from which we find evidence of heterogeneity. We identify individuals that follow either an aggregated or a disaggregated strategy, as well as others who seem to be using a combination of both strategies. We further analyze the heterogeneity hypothesis using an integrated discrete choice and latent class approach, which we apply to the same case study. This approach involves estimating path-size logit models built with alternatives from disaggregated and aggregated strategies, as well as a latent class model built from a combination of both. It also addresses methodological challenges related to the definition of the consideration set and the correction of endogeneity. Results confirm the heterogeneity hypothesis, suggesting that the mean probability that passengers belong to the class that uses a disaggregated strategy for route choice is 51.2%, and that this heterogeneity markedly occurs between individuals, not within their choices. We also find that the latent class considering aggregated alternatives appear to prefer bus over metro, while the latent class considering disaggregated alternatives prefer metro over bus. The fact that waiting time is relatively more burdensome for the aggregated strategy class is in line with this class’s preference for common lines. Walking time and bus crowding are more burdensome for the disaggregated strategy class, in line with their observed modal preferences.

Low-Density Granulocytes Are Decreased in Acute Myeloid Leukemia and in Myelodysplastic Syndromes with Negative Prognostic Factors

Introduction. Myelodysplastic syndromes (MDS), a group of clonal hematological diseases, are characterized by ineffective hematopoiesis, progressive peripheral blood (PB) cytopenia(s), and increased risk of developing acute myeloid leukemia (AML). Classification and risk stratification are constantly under revision for a better estimation of prognosis in those patients. Investigation of immune biomarkers is needed, because immune dysregulation also plays an important role in dysplastic hemopoiesis and immunological escape of neoplastic clones. Here, we studied frequency of low-density granulocytes (LDGs), a neutrophil subset with immunoregulatory functions, in MDS and AML at diagnosis and during treatments.Methods. A total of 17 patients (M/F, 14/12; median age, 69 years old; range, 21-84 years) and seven healthy subjects were enrolled at the Hematology and Transplant Center, University Hospital “San Giovanni di Dio e Ruggi d'Aragona”, Salerno, Italy, between October 2020 and July 2021. Patients were diagnosed with AML (N = 7), or MDS (N = 10) according to the 2016 World Health Organization criteria. For immunophenotyping, fresh EDTA whole PB was stained with the ollowing antibodies: CD45; HLA-DR; CD15; CD3; CD56; CD19; CD11b; CD33; CD34; CD14; and CD16 (all from Beckman Coulter, Brea, CA). Acquisition was carried out using a Navios EX flow cytometer, and Navios software v1.3 (Beckman Coulter). Post-acquisition compensation and analysis were performed using FlowJo software (v.10.7.1, Becton Dickinson). LDGs were identified as CD3-CD56-CD19-CD11b+CD33+CD14-CD15+ cells, following previously published gating strategies (Rahman S, et al. Ann Rheum Dis. 2019). Data were analyzed using Prism (GraphPad software, La Jolla, CA). A P < 0.05 was considered statistically significant.Results. Frequencies of circulating LDGs were significantly reduced in AML patients at diagnosis compared to controls (P = 0.0018) and MDS (P = 0.0077) and were slightly decreased compared to AML in complete remission (P = 0.1605). MDS patients were then divided based on Revised International Prognostic Scoring System (IPSS-R), and very-low and low-risk MDS patients displayed significantly higher circulating LDG frequencies compared to AML at diagnosis (P = 0.0083), while no differences were described between AML at baseline and intermediate-risk MDS (P = 0.1103). Subsequently, LDGs were correlated with clinical and phenotypic features by correlation analysis showing significant negative correlations between LDGs and blasts identified by flow cytometry (r = -0.5463; P = 0.0057) but not by cytology (P = 0.1346), between LDGs and lymphocytes (r = -0.4407; P = 0.0311) or flow cytometric normalized blast count (NBC; r = -0.5283; P = 0.0096) as previously defined (Giudice V, et al. Biomedicines. 2021). A slight negative correlation was described between LDGs and WT1 expression levels (r = -0.5369; P = 0.0719), particularly evident in MDS patients (r = -0.9980; P = 0.0402), supporting our previous findings of negative prognostic impact of WT1 expression in MDS and AML. Finally, we investigated CD16 expression on LDGs, because CD16 is essential for neutrophil degranulation. Despite no differences were described between percentage of LDG subsets among patients' groups, various correlations were identified by Pearson analysis. In particular, CD16+ LDGs negatively correlated with blasts (P = 0.0229), while positively correlated with lymphocytes (P = 0.0404) detected by flow cytometry. Conversely, CD16int and CD16- LDGs negatively correlated with lymphocytes (P = 0.0109 and P = 0.0021, respectively) and positively correlated with granulocytes identified by flow cytometry (P = 0.0024 and P = 0.0008, respectively). In addition, CD16int LDGs negatively correlated with blasts detected by flow cytometry (r = -0.65; P = 0.0414).Conclusions. Our preliminary results suggested a possible role of LDGs in prognostic definition of AML and MDS patients especially when combined with other biomarkers, such as WT1 expression levels or NBC. Moreover, our data supported the hypothesis of biological heterogeneity of granulocytes, as LDG subsets variously correlated with lymphocytes and leukemic cells suggesting different roles in suppression or activation of immune responses. However, our findings need further validation in larger cohorts and in in vitro studies. DisclosuresNo relevant conflicts of interest to declare.

Acres for the Affluent: An Interactive Model of Nonprofit Resources and Demand Heterogeneity

AbstractAccording to the theory of government failure, nonprofit organizations emerge when governments fail to provide goods or services to a public with heterogeneous demands. This study approaches this fundamental theory of the nonprofit sector from a pluralist political viewpoint, marrying the theory of government failure to resource-driven nonprofit arguments via updated modeling and measurement strategies. This article proposes a new, conditional demand heterogeneity hypothesis, wherein the effect of demand heterogeneity on the nonprofit sector increases in the presence of increasing resources: nonprofit service delivery is most likely when those experiencing government failure have access to resources. This article is the first to test supply and demand nonprofit arguments in tandem using an interactive modeling specification and the first to operationalize demand heterogeneity using policy-based measures. I employ a finite distributed lag model with an interactive term in a time series, cross-sectional analysis of public and nonprofit land conservation in the United States. I find that nonprofit land conservation increases when citizens express greater environmental concern but only in the presence of increasing disposable income. Examining nonprofit theory within the context of land conservation provides a comparable measure of government and nonprofit service provision, controls for the nature of the good provided by these institutions, and allows for a policy-driven measure of demand heterogeneity, improving upon previous studies’ employment of diversity-based proxy measures. The results advance our understanding of how to test and measure demand heterogeneity nonprofit arguments and suggest that access to resources conditions which interests find expression in nonprofit organizations.

Horizontal and vertical variation in the structure of fruit‐feeding butterfly (Nymphalidae) assemblages in the Brazilian Cerrado

Abstract The Cerrado biome is a biodiversity hotspot with a rich biota, and intense anthropogenic pressures. Despite its importance, it is still poorly understood how insects occupy different spatial dimensions of the landscape. We investigated how the beta diversity of plants influences the beta diversity of nymphalids at the regional‐scale (gallery forest vs. savannah) and local‐scale (transects). We expected greater beta‐diversity in nymphalid assemblages in gallery forests given the heterogeneity of plants and canopy structure. We sampled nymphalids in each habitat monthly for 1 year and observed 3459 individuals from 62 species. Nymphalidae abundance was significantly higher in the understory than in the canopy. Specifically, only 18% of the individuals were captured in the canopy of gallery forests compared to 11% in savannah canopies. Species richness was higher in gallery forests (55 species) compared to savannahs (34 species). Savannah transects were very similar in plant species composition and butterfly assemblages within the understory and canopy, whereas the species composition of plants and butterflies in gallery forests was highly heterogeneous which is consistent with the habitat heterogeneity hypothesis. Gallery forests are spatially more complex, which probably results in higher niche availability that may contribute to reduce the community saturation and help to maintain greater beta diversity in these habitats.

Essential fish habitats of demersal fish in the western Arabian Gulf

Information about habitats occupied by aquatic organisms while completing critical stages of their lives, called essential fish habitats, is crucial for their sustainability. In this work, we determine essential fish habitats (nursery and spawning grounds) of several fish species inhabiting Saudi territorial waters in the western Arabian Gulf using data from multiple surveys (2013–2016), geostatistics, and indicator species analysis. We built geostatistical maps of spatial distributions of juvenile and mature fish and examined the strength of association of each species to its observed nursery and spawning areas. Fish nursery areas were generally located in nearshore locations while spawning areas were located in offshore waters. The patterns of nursery and spawning grounds were highly varied among species, supporting a hypothesis of habitat-species heterogeneity: different species use different locations as nursery and spawning grounds. This information can be used as a roadmap for future evidence-based spatial planning and ecosystem-based management.

Explaining the Geographic Pattern of Plant Invasion in 67 Nature Reserves in China

Biological invasion is a serious threat to biodiversity and ecosystem function in nature reserves. However, the knowledge of the spatial patterns and underlying mechanisms of plant invasions in nature reserves is still limited. Based on a recent dataset on both invasive and native plants in 67 nature reserves of China, we used correlation, regression, and variation partitioning methods to statistically assess the relative roles of the “human activity,” “biotic acceptance,” and “environmental heterogeneity” hypotheses in explaining the geographic pattern of plant invasion. A total of 235 invasive plant species were compiled from 67 nature reserves. The high explanatory power of the human activity variables supported the human activity hypothesis. The biotic acceptance hypothesis was weakly supported since no significant correlations between climatic variables and invasion levels were found when the effects of the other factors were controlled. The environmental heterogeneity hypothesis was partially supported, since the number of native plants, representing environmental heterogeneity at fine-scale explained remarkable proportion of spatial variance of invasive plants but not that of the proportion of invasive plants. We predict that nature reserves with high plant diversity affected by rapid economic development and increasing temperature will face a serious threat of exotic plant invasion. In conclusion, our results provide crucial clues for understanding geographic variance of plant invasion in China’s nature reserves and spatial risk assessment.

Differences in Mental Health and Bullying Victimization Experiences between Youth of Different Sexualities: A Bayesian Perspective

ABSTRACT Researchers have extensively investigated the differences in mental health and bullying victimization experiences of adolescents of different sexualities. Prior research has typically sought differences between heterosexual and non-heterosexual (homosexual and bisexual, combined) youth or between heterosexual, homosexual and bisexual youth. These two routes of research are based on different assumptions about where the differences lie. The current study is the first to compare the assumptions of these two routes of research. We transformed the respective assumptions to two competing hypotheses: the homogeneity hypothesis, which states that differences lie between heterosexual and non-heterosexual youth (homosexual and bisexual youth are thus considered a homogeneous group), and the heterogeneity hypothesis, which states that differences lie between heterosexual, homosexual and bisexual youth (homosexual and bisexual youth are not considered a homogeneous group). We administered a demographic form and a battery of questionnaires on mental health, mental illness, and on general and homophobic bullying to 757 Greek secondary education students. We used Bayesian statistics, because they allow comparing the support that two competing hypotheses receive from empirical data. The results provided more support to the hypothesis that there are differences in the mental health and bullying experiences between heterosexual and non-heterosexual youth. However, in some of the conducted comparisons, no conclusion could be drawn in favor of any of the two hypotheses.