Mass Transfer Characteristics of Immobilized Cells Used in Fermentation Processes

ABSTRACT:?

There is great commercial interest in using immobilized cells for fermented beverage processes. The process advantages offered by immobilized cells are numerous, but an understanding of the mass transfer characteristics of a given system is needed in order to achieve efficient processes and high quality products. This is especially important in the food and beverage industry where fermentation products contribute to the flavor and aroma of the final product. The fundamental principles of mass transfer in immobilized cell systems are covered in this review. An overview of the current research efforts focused on external and internal mass transfer characteristics of immobilized cells used in fermentation processes is presented. Methods for measuring substrate diffusivities within immobilization matrices and areas requiring further research are discussed.     

A multidimensional concept for mercury neuronal and sensory toxicity in fish - From toxicokinetics and biochemistry to morphometry and behavior

BackgroundNeuronal and sensory toxicity of mercury (Hg) compounds has been largely investigated in humans/mammals with a focus on public health, while research in fish is less prolific and dispersed by different species. Well-established premises for mammals have been governing fish research, but some contradictory findings suggest that knowledge translation between these animal groups needs prudence [e.g. the relative higher neurotoxicity of methylmercury (MeHg) vs. inorganic Hg (iHg)]. Biochemical/physiological differences between the groups (e.g. higher brain regeneration in fish) may determine distinct patterns. This review undertakes the challenge of identifying sensitive cellular targets, Hg-driven biochemical/physiological vulnerabilities in fish, while discriminating specificities for Hg forms.Scope of reviewA functional neuroanatomical perspective was conceived, comprising: (i) Hg occurrence in the aquatic environment; (ii) toxicokinetics on central nervous system (CNS)/sensory organs; (iii) effects on neurotransmission; (iv) biochemical/physiological effects on CNS/sensory organs; (v) morpho-structural changes on CNS/sensory organs; (vi) behavioral effects. The literature was also analyzed to generate a multidimensional conceptualization translated into a Rubik’s Cube where key factors/processes were proposed.Major conclusionsHg neurosensory toxicity was unequivocally demonstrated. Some correspondence with toxicity mechanisms described for mammals (mainly at biochemical level) was identified. Although the research has been dispersed by numerous fish species, 29 key factors/processes were pinpointed.General significanceFuture trends were identified and translated into 25 factors/processes to be addressed. Unveiling the neurosensory toxicity of Hg in fish has a major motivation of protecting ichtyopopulations and ecosystems, but can also provide fundamental knowledge to the field of human neurodevelopment.     

Linguistic and Activity Relativity in Cognition

Abstract

This work compares the features of cognitive processes uncovered in experimental studies undertaken to test the Sapir-Whorf hypothesis with cultural features of thinking that are shaped by activity-related factors rather than by language that have been identified by cross-cultural research into thinking. It is concluded that this latter area of research has uncovered more essential differences in cognitive processes. There is discussion of the linguistic aspect of activity-related differences in thinking, in particular the possibility of using Hymes’ idea of functional linguistic relativity in cross-cultural research. The article concludes with a discussion of possible social-psychological reasons why the linguistic-relativity phenomenon is more popular than activity-related relativity.     

基于单分子量子相干调制的细胞温度成像技术

目的 细胞温度成像可以帮助科学家研究和理解细胞内部的温度分布,揭示细胞代谢和生物化学过程的关键信息。目前,基于荧光温度探针的细胞温度成像技术存在低温度分辨率和有限测量范围等限制。本文旨在利用单分子量子相干过程依赖温度的特性,开发一种单细胞温度成像和实时检测技术。方法 基于飞秒脉冲激光制备延时和相位可调的飞秒脉冲对,调制的脉冲对通过显微系统激发细胞内标记的荧光单分子,之后收集并记录每个荧光光子的到达时间。利用单分子相干过程与周围环境温度的关系,定义单分子量子相干可视度（V）,建立V与环境温度的对应关系。通过调制解调荧光光子的到达时间,获取单分子周围环境温度,结合扫描成像,实现细胞的温度成像和实时检测。结果 该方法可以实现高精度（温度分辨率<0.1℃）和大范围温度（10～50℃）的温度成像和测量,并观测到了单个细胞代谢相关的温度变化。结论 该研究有助于深入了解细胞代谢、蛋白质功能和疾病机制,为生物医学研究提供重要工具。     

基于比较转录组分析海洋弧菌X511的褐藻胶代谢途径

【目的】从北海涠洲岛海域腐烂的马尾藻中分离得到的海洋弧菌(Vibrio X511)具有较强的利用褐藻胶能力,本文利用转录组测序的方法以研究弧菌X511的褐藻胶代谢途径。【方法】采用Illumina Hi Seq2500测序平台对菌株在褐藻胶及葡萄糖培养下的转录组进行测序;比较和分析差异转录本,利用荧光定量PCR验证测序结果;采用GO(Gene Ontology)和KEGG(Kyoto Encyclopedia of Genes and Genomes)对差异转录本进行功能和Pathway注释。【结果】经比较发现,菌株在褐藻胶培养下相对于葡萄糖的培养共有2024个差异表达基因,其中1066个基因上调,958个基因下调;某些普遍存在于代谢途径中的基因在不同培养条件下也存在差异表达;海洋弧菌X511中涉及褐藻胶利用的所有基因以及合成乙醇的关键基因其转录量均有一定程度的上调;此外,通过分析发现该菌株具有独特的褐藻胶利用方式,其中的一个代谢过程尚未在弧菌中被报道。【结论】成功解析了海洋弧菌X511的褐藻胶代谢途径,丰富了生物方法降解褐藻胶的研究,为大型海藻生物质能源的研究提供有价值的数据支持。     

Iron-associated biology of Trypanosoma brucei

BackgroundEvery eukaryote requires iron, which is also true for the parasitic protist Trypanosoma brucei, the causative agent of sleeping sickness in humans and nagana in cattle. T. brucei undergoes a complex life cycle during which its single mitochondrion is subject to major metabolic and morphological changes.Scope of reviewThis review covers what is known about processes associated with iron–sulfur clusters and heme metabolism in T. brucei. We discuss strategies by which iron and heme are acquired and utilized by this model parasite, emphasizing the differences between its two life cycle stages residing in the bloodstream of the mammalian host and gut of the insect vector. Finally, the role of iron in the host–parasite interactions is discussed along with their possible exploitation in fighting these deadly parasites.Major conclusionsThe processes associated with acquisition and utilization of iron, distinct in the two life stages of T. brucei, are fine tuned for the dramatically different host environment occupied by them. Although the composition and compartmentalization of the iron–sulfur cluster assembly seem to be conserved, some unique features of the iron acquisition strategies may be exploited for medical interventions against these parasites.General significanceAs early-branching protists, trypanosomes and related flagellates are known to harbor an array of unique features, with the acquisition of iron being another peculiarity. Thanks to intense research within the last decade, understanding of iron–sulfur cluster assembly and iron metabolism in T. brucei is among the most advanced of all eukaryotes.     

Ecological research in the tropical alpine ecosystems of the Venezuelan páramo: past,present and future

ABSTRACT

Background: Tropical mountain ecosystems of the Northern Andes have long fascinated researchers because of the unique conditions associated with cold climates in equatorial latitudes. More than six decades have elapsed since the beginning of systematic ecological research in the Venezuelan páramos, making them one of the best-studied tropical alpine regions in the world.

Aims: We review the conceptual development and state of the art of ecological research in the Venezuelan páramos, with emphasis on environmental and plant ecology research, presenting a general framework for the studies included in this special issue.

Methods: We provide a historical sketch of the periods that have marked ecological studies in the Venezuelan páramos. Then, we synthesise research on environmental drivers, plant population and community ecology, ecosystem functioning, the response of the páramo to climate change and human disturbance; we finally consider agroecology and conservation.

Results and conclusions: This review demonstrates the significant contributions made to alpine ecology in key areas such as biodiversity/ecosystem function changes during succession, nutrient cycling, species interactions and socio-ecological research. We indicate the need to develop a more integrated view of the links between evolutionary processes, functional diversity, community dynamics and ecosystem services both in natural and human-impacted areas.     

ViBiBa: Virtual BioBanking for the DETECT multicenter trial program - decentralized storage and processing

BackgroundLiquid Biopsy (LB) in the form of e.g., circulating tumor cells (CTCs) is a promising non-invasive approach to support current therapeutic cancer management. However, the proof of clinical utility of CTCs in informing therapeutic decision-making for e.g., breast cancer in clinical trials and associated translational research projects is facing the issues of low CTC positivity rates and low CTC numbers – even in the metastasized situation. To compensate for this dilemma, clinical CTC trials are designed as large multicenter endeavors with decentralized sample collection, processing and storage of products, making data management highly important to enable high-quality translational CTC research.AimIn the DETECT clinical CTC trials we aimed at developing a custom-made, browser-based virtual database to harmonize and organize both decentralized processing and storage of LB specimens and to enable the collection of clinically meaningful LB sample.MethodsViBiBa processes data from various sources, harmonizes the data and creates an easily searchable multilayered database.ResultsAn open-source virtual bio-banking web-application termed ViBiBa was created, which automatically processes data from multiple non-standardized sources. These data are automatically checked and merged into one centralized databank and are providing the opportunity to extract clinically relevant patient cohorts and CTC sample collections.SummaryViBiBa, which is a highly flexible tool that allows for decentralized sample storage of liquid biopsy specimens, facilitates a solution which promotes collaboration in a user-friendly, federalist and highly structured way. The source code is available under the MIT license from https://vibiba.com or https://github.com/asperciesl/ViBiBa     

WETLANDS AS ACCRETING SYSTEMS: NUTRIENT CYCLING IN WETLANDS

SUMMARY

The major concepts involved in nutrient cycling in wetlands are discussed using phosphorus and nitrogen as examples. The differences in nutrient cycling patterns between hydrologically contrasting wetlands, and the significance of fluctuating water levels in wetlands, are stressed. In South Africa, some research into nutrient cycling in submerged aquatic macrophyte communities has been undertaken, but very little information is available on these processes in wetlands dominated by emergent vegetation forms. Generally, the information available on nutrient cycling processes in South African wetlands is of limited applicability to the assessment of nutrient cycling in whole wetland systems. Therefore, rational wetland management strategies require further research on nutrient cycling.     

Factors Affecting Accuracy of Data Abstracted from Medical Records

ObjectiveMedical record abstraction (MRA) is often cited as a significant source of error in research data, yet MRA methodology has rarely been the subject of investigation. Lack of a common framework has hindered application of the extant literature in practice, and, until now, there were no evidence-based guidelines for ensuring data quality in MRA. We aimed to identify the factors affecting the accuracy of data abstracted from medical records and to generate a framework for data quality assurance and control in MRA.MethodsCandidate factors were identified from published reports of MRA. Content validity of the top candidate factors was assessed via a four-round two-group Delphi process with expert abstractors with experience in clinical research, registries, and quality improvement. The resulting coded factors were categorized into a control theory-based framework of MRA. Coverage of the framework was evaluated using the recent published literature.ResultsAnalysis of the identified articles yielded 292 unique factors that affect the accuracy of abstracted data. Delphi processes overall refuted three of the top factors identified from the literature based on importance and five based on reliability (six total factors refuted). Four new factors were identified by the Delphi. The generated framework demonstrated comprehensive coverage. Significant underreporting of MRA methodology in recent studies was discovered.ConclusionThe framework generated from this research provides a guide for planning data quality assurance and control for studies using MRA. The large number and variability of factors indicate that while prospective quality assurance likely increases the accuracy of abstracted data, monitoring the accuracy during the abstraction process is also required. Recent studies reporting research results based on MRA rarely reported data quality assurance or control measures, and even less frequently reported data quality metrics with research results. Given the demonstrated variability, these methods and measures should be reported with research results.     

Disturbance reinforces community assembly processes differentially across spatial scales

Background and AimsThere is a paucity of empirical research and a lack of predictive models concerning the interplay between spatial scale and disturbance as they affect the structure and assembly of plant communities. We proposed and tested a trait dispersion-based conceptual model hypothesizing that disturbance reinforces assembly processes differentially across spatial scales. Disturbance would reinforce functional divergence at the small scale (neighbourhood), would not affect functional dispersion at the intermediate scale (patch) and would reinforce functional convergence at the large scale (site). We also evaluated functional and species richness of native and exotic plants to infer underlying processes. Native and exotic species richness were expected to increase and decrease with disturbance, respectively, at the neighbourhood scale, and to show similar associations with disturbance at the patch (concave) and site (negative) scales.MethodsIn an arid shrubland, we estimated species richness and functional dispersion and richness within 1 m² quadrats (neighbourhood) nested within 100 m² plots (patch) along a small-scale natural disturbance gradient caused by an endemic fossorial rodent. Data for the site scale (2500 m² plots) were taken from a previous study. We also tested the conceptual model through a quantitative literature review and a meta-analysis.Key ResultsAs spatial scale increased, disturbance sequentially promoted functional divergence, random trait dispersion and functional convergence. Functional richness was unaffected by disturbance across spatial scales. Disturbance favoured natives over exotics at the neighbourhood scale, while both decreased under high disturbance at the patch and site scales.ConclusionsThe results supported the hypothesis that disturbance reinforces assembly processes differentially across scales and hampers plant invasion. The quantitative literature review and the meta-analysis supported most of the model predictions.     

Human proline specific peptidases: A comprehensive analysis

BackgroundProline specific peptidases (PSPs) are a unique group of enzymes that specifically cleave bonds formed by a proline residue. The study of PSPs is important due to their role in the maturation and degradation of peptide hormones and neuropeptides. In addition, changes in the activity of PSPs can result in pathological conditions, including various types of cancer.Scope of reviewPSPs annotated from the Homo sapiens genome were compared and classified by their physicochemical and biochemical features and roles in vital processes. In addition to catalytic activity, we discuss non-enzymatic functions that may regulate cellular activity.Major conclusionsPSPs apparently have multiple functions in animals. Two functions rely on the catalytic activity of the enzyme: one involved in a regulatory pathway associated with the ability of many PSPs to hydrolyze peptide hormones and neuropeptides, and the other involved in the trophic pathway associated with the proteolysis of total cellular protein or Pro-containing dietary proteins in the digestive tract. PSPs also participate in signal transduction without proteolytic activity by forming protein-protein interactions that trigger or facilitate the performance of certain functions.General significancePSPs are underestimated as a unique component of the normal human peptidase degradome, providing the body with free proline. A comparative analysis of PSPs can guide research to develop inhibitors that counteract the abnormalities associated with changes in PSP activity, and identify natural substrates of PSPs that will enable better understanding of the mechanisms of the action of PSPs in biological processes and disease.     

Innovando en la toma de decisiones compartida con pacientes hospitalizados: descripción y evaluación de una herramienta de registro de nivel de intensidad terapéutica

Background and aimShared decision-making between patients and healthcare professionals is crucial to guarantee adequate coherence between patient values and preferences, caring aims and treatment intensity, which is key for the provision of patient-centred healthcare. The assessment of such interventions are essential for caring continuity purposes. To do this, reliable and easy-to-use assessment systems are required. This study describes the results of the implementation of a hospital treatment intensity assessment tool.Material and methodsThe pre-implementation and post-implementation results were compared between two cohorts of patients assessed for one month.ResultsSome record of care was registered in 6.1% of patients in the pre-implementation group (n = 673) compared to 31.6% of patients in the post-implementation group (n = 832) (P < .01), with differences between services. Hospital mortality in both cohorts is 1.9%; in the pre-implementation group, 93.75% of deceased patients had treatment intensity assessment.ConclusionsIn hospital settings, the availability of a specific tool seems to encourage very significantly shared decision-making processes between patients and healthcare professionals —multiplying by more than 5 times the treatment intensity assessment. Moreover, such tools help in the caring continuity processes between different teams and the personalisation of caring interventions to be monitored. More research is needed to continue improving shared decision-making for hospital patients     

Inflammatory bowel disease - glycomics perspective

BackgroundInflammatory bowel disease (IBD) pathogenesis is still not well understood. It is considered to result from genetic susceptibility, environment, microbiota composition and aberrant immune response. Crohn's disease (CD) and ulcerative colitis (UC), forms of IBD, are sometimes indistinguishable by typical laboratory and clinical characteristics making timely diagnosis and subsequent therapy hit-and-miss. Glycosylation has shown a promising biomarker potential for early IBD diagnosis and effective response to treatment prediction.Scope of reviewThis mini-review briefly covers present knowledge of IBD pathophysiology, with a focus on recent research on the role of glycosylation in IBD pathogenesis and disease progression.Major conclusionsAberrant glycosylation significantly changes functionality of key proteins in intestinal niche and is involved in IBD etiology.General significanceElucidating mechanisms of IBD development is one of critical goals in managing this disease. Glycans are important for fine-tuning of intestinal processes that ensure homeostatic conditions which, if disrupted, lead to IBD.     

Trait dynamics of Mediterranean xerophytic shrub communities growing on stabilised inland dunes respond to nutrient and aridity gradients

Background: Understanding the processes that determine community assembly and their dynamics is a central issue in ecology. The analysis of functional diversity can improve our understanding of these dynamics by identifying community assembly processes.

Aims: We studied the effect of environment–community covariations on both functional diversity and functional structure of xerophytic shrub communities for inferring the community assembly processes shaping this vegetation type.

Methods: Functional diversity was quantified using (1) community-weighted mean of the studied traits, (2) functional groups, defined using Ward’s hierarchical agglomerative clustering method and (3) Rao’s quadratic entropy. Relationships between functional diversity and environmental gradients were identified by Spearman correlations and modelled using generalised additive models.

Results: Variations in community composition and functional diversity correlated with soil nutrient availability and aridity. Increasing nutrient availability resulted in both greater average plant height and higher abundance of plants with green photosynthetic organ colour, whereas the abundance of nanophanerophytes increases with aridity.

Conclusions: The species composition and trait structure of the studied Mediterranean xerophytic shrub communities varies along nutrient and aridity gradients. This supports the importance of environmental filters for the local assembly and dynamics of these inland dune communities.     

S-Glutathiolation in life and death decisions of the cell

Abstract

Reversible S-glutathiolation of specific proteins at sensitive cysteines provides a powerful mechanism for the dynamic, post-translational regulation of many cellular processes, including apoptosis. Critical in ascribing any regulatory function to S-glutathiolation is its reversibility, mainly regulated by glutaredoxins. Apoptosis is a controlled form of cell death that plays fundamental roles during embryonic development, tissue homeostasis and some diseases. Much of what happens during the demolition phase of apoptosis is orchestrated primarily by caspases, the final executioners of cell death. Recent findings support an essential role for S-glutathiolation in apoptosis, often at the level of caspases or their inactive precursors, and several studies have demonstrated the importance of glutaredoxins in protecting against apoptosis. These observations have contributed to recent advances in apoptosis research. However, the effective relevance of protein S-glutathiolation and the precise molecular targets in apoptotic signalling remain unresolved and a key challenge for future research.     

A review of the current (1992) state of our knowledge concerning reproduction in open thelycum Penaeid shrimp with emphasis on Penaeus vannamei

Summary

The current state of knowledge relating to the reproduction of the commercially important open thelycum shrimps (Crustacea: Penaeidae) is reviewed with particular reference to Penaeus vannamei. Industry standard procedures for the breeding of shrimps in captivity are reviewed against a background of knowledge concerning the maturation processes in males and females. The factors controlling maturation are not completely understood, and it is not clear whether maturation of females is size-or age-dependent. Although unilateral eyestalk ablation is routinely used to induce maturation, the physiological mechanism of this operation is not properly understood. Further research on environmental conditions for successful maturation is required. Nutrition is an important component in successful artificial breeding programs that still rely on the provision of natural foods (squid and polychaeta). The processes of oocyte formation, mating, spawning and hatching are discussed in relation to observations made at the Gulf Coast Research Laboratory.     

基于文献计量分析土壤微生物对气候变暖的响应

【背景】面对全球气候变暖,土壤微生物在陆地生态系统对全球变暖反馈中起到了至关重要的作用。【目的】了解土壤微生物对气候变暖响应研究的发展现状、研究热点及前沿动态,厘清当前该研究领域的知识结构关系。【方法】以1999-2021年Web of Science核心数据库中土壤微生物对气候变暖响应研究已发表的3 189篇论文为数据源,利用Vosviewer和CiteSpace软件对年发文量、文献被引频次、作者、机构、国家、学科和关键词等进行可视化分析。【结果】研究总体呈逐步增长趋势,经历缓慢增长、稳步增长和高速增长3个阶段;高被引论文均发表在国际顶级期刊上,研究成果具有较高的学术影响力。在学科融合与合作交流方面,环境科学、生态学和土壤学是该研究领域的主要学科,而多学科交叉学在该领域占有重要地位;作者骆亦其、Schuur和周集中是该领域核心学者,作者之间的合作关系主要以同一研究团队内部合作为主;主要的科研机构有中国科学院、加利福尼亚大学和美国能源部,各科研机构之间合作较为紧密;中国、美国和欧洲是土壤微生物对气候变暖响应研究领域的主要力量,国家之间相互合作程度高。该领域的主要研究热点是气候变暖改变了土壤微生物的群落结构组成、多样性和生理生化功能,进而对地球化学物质循环产生影响;土壤微生物在土壤碳库释放中的作用机理和调控机制是该领域研究前沿。【结论】目前,不同生态系统研究中土壤微生物对增温的响应与适应机制存在着差异,而且对微生物碳功能基因和多环境交互因子的研究较少。因此,建议后期应更加聚焦特定生态系统的细化研究,开展大范围、大尺度、长时期的定位研究,加强对微生物碳降解和碳固定功能基因的研究,多关注环境因子变化的交互作用对土壤微生物生态过程的影响。