Purpose
The purpose of this paper is to refract March’s views on leadership to re-frame them within an authentic model that understands optimistic failure and mindful resilience as likely byproducts ...of enabling ambiguous innovation. An analysis of March’s theories of slack, and the concepts of exploration and exploitation, as well as that of foolishness, are used to support the adoption of authentic and ethical leadership as an intelligent practice and, more concretely, to portray the leader as a resilient “juggling fool.”
Design/methodology/approach
This paper makes use of primary data by focusing on March’s published works, as well as on interviews and other materials written about him, or those discussing his contributions. A post-hoc practice of “appreciation” facilitated a fresh refraction of the “evidence” to identify or recognize new perspectives and/or challenges to March’s conceptualization of leadership, while relying on literature and metaphor to engage in “polymorphic research.”
Findings
This paper presents March as a complex thinker, whose thoughts on leadership have received, perhaps, less attention for being thought to be more refractive and less empirical. Nonetheless, his reflections on leadership re-discover him as a solid leadership philosopher. His use of literature, his theories of slack and the concepts of exploration and exploitation, as well as that of foolishness, may help leadership scholars to understand the essence of authentic and ethical leadership as an intelligent practice.
Practical implications
This paper proposes to extrapolate March’s vast insights about organizational theory to further develop the framework of authentic leadership. This re-framing of the leader as a “juggling fool” constitutes an empowered view of leadership that comes closer to balancing the complementary purposes of leadership and management; an effort that rests at the core of the future of leadership.
Originality/value
Despite the ostensible popularity of leadership over management as a desired organizational outcome, March’s phenomenal insights remind current and developing leaders of just how much the two fields must overlap in constant tension. It is, perhaps, the conceptualization of a leader as an authentic and resilient “juggling fool” what adds depth of meaning to March’s contributions to the field of leadership beyond that of management.
A direct spectrophotometric method for the determination of three artificial colors – amaranth, sunset yellow FCF and tartrazine – in beverages samples is proposed. The spectra were recorded between ...359 and 600
nm. The spectra of the samples (just filtrated), pure dyes (concentrations ranged between 0.01 and 1.8
mg
L
−1 for amaranth, 0.08 and 4.4
mg
L
−1 for sunset yellow and 0.04 and 1.8
mg
L
−1 for tartrazine) and synthetic mixtures were disposed in a column-wise augmented data matrix. This kind of data structure, analyzed by multivariate curve resolution-alternating least squares (MCR-ALS) makes it possible to exploit the so called ‘second order advantage’. MCR-ALS algorithm was applied to the experimental data under the non-negativity and equality constraints. As a result, the concentration of each dye in the samples and their corresponding pure spectra were obtained.
The results were validated using internal reference materials and no significant differences were found (
α
=
5%) between the reference values and the ones obtained with the proposed method. The second order advantage made it possible to obtain unbiased results even in the presence of interferences.
1α,25-Dihydroxyvitamin D3 1α,25-(OH)2-D3, the hormonally active form of vitamin D3, classically regulates bone formation, calcium, and phosphate homeostasis. In addition, this hormone also exerts ...non-classical effects in a wide variety of target tissues and cell types, such as inhibition of the proliferation and stimulation of the differentiation of normal and malignant cells. However, to produce these actions, supraphysiological doses are required resulting in calcemic effects that limit the use of this natural hormone. During the past 30 years, many structurally modified analogs of the 1α,25-(OH)2-D3 have been synthesized in order to find derivatives that can dissociate the beneficial antiproliferative effects from undesired calcemic effects. Among these candidates, 1α,25-(OH)2-19-nor-D3 analogs have shown promise as good derivatives since they show equal or better activity relative to the parent hormone but with reduced calcemic effects. In this review, we describe the synthetic strategies to obtain the 19-nor-D3 derivatives and briefly describe their physiological activities.
Heavy metal pollution can result in the degradation of the soil, air and water bodies' quality affecting the health of all living organism. We analyze the spatial distribution of the concentrations ...of soil heavy metal and relationship with natural or anthropogenic origin. The analysis was performed in Principality of Asturias (mountain region of NW of Spain), where soil heavy metal pollution has become a severe problem. First, a standard Principal Components Analysis (PCA) was performed over a population of 334 soil samples to identify the sources of fourteen heavy metal and metalloids (Ag, As, Ba, Hg, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Zn). Due to the high geological heterogeneity of the territory, the PCA analysis was improved using a variant of PCA known as Geographically Weighted Principal Components Analysis (GWPCA). The first six principal components in a standard PCA account for about 57% of soil heavy metal variability but when GWPCA is performed this figure increases to >80% in some areas. We conclude that GWPC1 corresponds to a geogenetic component with changing winning variables adapted to the geological characteristics of the territory (lithology and mining), while GWPC2 corresponds to a factor related to atmospheric pollution including heavy metal released from vegetation cover via wildfires.
•GWPCA method improves the explanation of the spatial distribution of soil heavy metal.•Winning variables from GWPCA analysis are related to geogenetic and atmospheric sources.•Ashes from wildfires could be a source of soil heavy metal pollution.
Multi-agent planning (MAP) deals with planning systems that reason on long-term goals by multiple collaborative agents which want to maintain privacy on their knowledge. Recently, new MAP techniques ...have been devised to provide efficient solutions. Most approaches expand distributed searches using modified planners, where agents exchange public information. They present two drawbacks: they are planner-dependent; and incur a high communication cost. Instead, we present two algorithms whose search processes are monolithic (no communication while individual planning) and MAP tasks are compiled such that they are planner-independent (no programming effort needed when replacing the base planner). Our two approaches first assign each public goal to a subset of agents. In the first
distributed
approach, agents iteratively solve problems by receiving plans, goals and states from previous agents. After generating new plans by reusing previous agents’ plans, they share the new plans and some obfuscated private information with the following agents. In the second
centralized
approach, agents generate an obfuscated version of their problems to protect privacy and then submit it to an agent that performs centralized planning. The resulting approaches are efficient, outperforming other state-of-the-art approaches.
► Equitability ordering describes forest structure better than diversity indices. ► Even- and uneven-sized stands are intrinsically non-comparable using diversity indices. ► No index should be ...presented without testing intrinsic ordering assumption. ► Lorenz method is the most reliable for discrimination of forest structural types. ► Lorenz curves from tree sizes best compare with theoretical uniform distribution.
This article performs an in-depth examination on whether indices of diversity and equitability among tree size classes are adequate for studying the structural complexity of forests. Diversity profiles and the intrinsic diversity ordering of several field plots were compared. Results demonstrated that even-sized stands are intrinsically non-comparable to uneven-sized stands with regard to their diversity of size classes. Indices describing the diversity of size classes are consequently inadequate, as they order forest structural types (FSTs) inconsistently. The concept of equitability, obtained when removing the richness component from entropy, seemed more adequate for this purpose. Indices of equitability among size classes provided more consistent measures, since the field plots had comparable intrinsic equitability ordering. Furthermore, ranking individual trees by their size is a better approach than ranking size classes, and therefore it is more correct to measure the inequality of tree sizes rather than equitability among size classes. A particular interpretation of Lorenz curves applies when they are used for the study of forest structures, as they should also be compared to a theoretical uniform distribution, and not just the diagonal line-of-absolute-equality. Advised indices are Gini coefficient (GC), De Camino homogeneity (CH), and structure index based on variance (STVI), as they all are consistent with the Lorenz ordering.
Alzheimer's disease and its complications are the leading cause of death in adults with Down syndrome. Studies have assessed Alzheimer's disease in individuals with Down syndrome, but the natural ...history of biomarker changes in Down syndrome has not been established. We characterised the order and timing of changes in biomarkers of Alzheimer's disease in a population of adults with Down syndrome.
We did a dual-centre cross-sectional study of adults with Down syndrome recruited through a population-based health plan in Barcelona (Spain) and through services for people with intellectual disabilities in Cambridge (UK). Cognitive impairment in participants with Down syndrome was classified with the Cambridge Cognitive Examination for Older Adults with Down Syndrome (CAMCOG-DS). Only participants with mild or moderate disability were included who had at least one of the following Alzheimer's disease measures: apolipoprotein E allele carrier status; plasma concentrations of amyloid β peptides 1–42 and 1–40 and their ratio (Aβ1–42/1–40), total tau protein, and neurofilament light chain (NFL); tau phosphorylated at threonine 181 (p-tau), and NFL in cerebrospinal fluid (CSF); and one or more of PET with 18F-fluorodeoxyglucose, PET with amyloid tracers, and MRI. Cognitively healthy euploid controls aged up to 75 years who had no biomarker abnormalities were recruited from the Sant Pau Initiative on Neurodegeneration. We used a first-order locally estimated scatterplot smoothing curve to determine the order and age at onset of the biomarker changes, and the lowest ages at the divergence with 95% CIs are also reported where appropriate.
Between Feb 1, 2013, and June 28, 2019 (Barcelona), and between June 1, 2009, and Dec 31, 2014 (Cambridge), we included 388 participants with Down syndrome (257 66% asymptomatic, 48 12% with prodromal Alzheimer's disease, and 83 21% with Alzheimer's disease dementia) and 242 euploid controls. CSF Aβ1–42/1–40 and plasma NFL values changed in individuals with Down syndrome as early as the third decade of life, and amyloid PET uptake changed in the fourth decade. 18F-fluorodeoxyglucose PET and CSF p-tau changes occurred later in the fourth decade of life, followed by hippocampal atrophy and changes in cognition in the fifth decade of life. Prodromal Alzheimer's disease was diagnosed at a median age of 50·2 years (IQR 47·5–54·1), and Alzheimer's disease dementia at 53·7 years (49·5–57·2). Symptomatic Alzheimer's disease prevalence increased with age in individuals with Down syndrome, reaching 90–100% in the seventh decade of life.
Alzheimer's disease in individuals with Down syndrome has a long preclinical phase in which biomarkers follow a predictable order of changes over more than two decades. The similarities with sporadic and autosomal dominant Alzheimer's disease and the prevalence of Down syndrome make this population a suitable target for Alzheimer's disease preventive treatments.
Instituto de Salud Carlos III, Fundació Bancaria La Caixa, Fundació La Marató de TV3, Medical Research Council, and National Institutes of Health.
Diagnosis of Alzheimer's disease in Down syndrome is challenging because of the absence of validated diagnostic biomarkers. We investigated the diagnostic performance of plasma and CSF biomarkers in ...this population.
We did a cross-sectional study of adults aged 18 years and older with Down syndrome enrolled in a population-based health plan in Catalonia, Spain. Every person with Down syndrome assessed in the health plan was eligible to enter the Down Alzheimer Barcelona Neuroimaging Initiative, and those with a plasma or CSF sample available were included in this study. Participants underwent neurological and neuropsychological examination and blood sampling, and a subset underwent a lumbar puncture. Adults with Down syndrome were classified into asymptomatic, prodromal Alzheimer's disease, or Alzheimer's disease dementia groups by investigators masked to biomarker data. Non-trisomic controls were a convenience sample of young (23–58 years) healthy people from the Sant Pau Initiative on Neurodegeneration. Amyloid-β (Aβ)1–40, Aβ1–42, total tau (t-tau), 181-phosphorylated tau (p-tau; only in CSF), and neurofilament light protein (NfL) concentrations were measured in plasma with a single molecule array assay and in CSF with ELISA. Plasma and CSF biomarker concentrations were compared between controls and the Down syndrome clinical groups. Diagnostic performance was assessed with receiver operating characteristic curve analyses between asymptomatic participants and those with prodromal Alzheimer's disease and between asymptomatic participants and those with Alzheimer's disease dementia.
Between Feb 1, 2013, and Nov 30, 2017, we collected plasma from 282 participants with Down syndrome (194 asymptomatic, 39 prodromal Alzheimer's disease, 49 Alzheimer's disease dementia) and 67 controls; CSF data were available from 94 participants (54, 18, and 22, respectively) and all 67 controls. The diagnostic performance of plasma biomarkers was poor (area under the curve AUC between 0·53 95% CI 0·44–0·62 and 0·74 0·66–0·82) except for plasma NfL concentrations, which had an AUC of 0·88 (0·82–0·93) for the differentiation of the asymptomatic group versus the prodromal Alzheimer's disease group and 0·95 (0·92–0·98) for the asymptomatic group versus the Alzheimer's disease dementia group. In CSF, except for Aβ1–40 concentrations (AUC 0·60, 95% CI 0·45–0·75), all biomarkers had a good performance in the asymptomatic versus prodromal Alzheimer's disease comparison: AUC 0·92 (95% CI 0·85–0·99) for Aβ1–42, 0·81 (0·69–0·94) for t-tau, 0·80 (0·67–0·93) for p-tau, and 0·88 (0·79–0·96) for NfL. Performance of the CSF biomarkers was optimal in the asymptomatic versus Alzheimer's disease dementia comparison (AUC ≥0·90 for all except Aβ1–40 0·59, 0·45–0·72). Only NfL concentrations showed a strong correlation between plasma and CSF biomarker concentrations in participants with Down syndrome (rho=0·80; p<0·0001).
Plasma NfL and CSF biomarkers have good diagnostic performance to detect Alzheimer's disease in adults with Down syndrome. Our findings support the utility of plasma NfL for the early detection of Alzheimer's disease in Down syndrome in clinical practice and clinical trials.
Institute of Health Carlos III, Fundació La Marató de TV3, Fundació Bancaria Obra Social La Caixa, Fundació Catalana Síndrome de Down, and Fundació Víctor Grífols i Lucas.
Wild foods contribute to the food security of multiple communities in tropical areas of Africa, Asia and Latin America. However, wild foods are not regularly considered in the planning of strategies ...for food and nutrition security mainly due to the lack of technical and/or scientific knowledge so that they can be considered suitable for human consumption. This paper proposes a multidisciplinary method that estimates the potential of wild foods as alternative resources when planning interventions in favour of food and nutrition security in tropical forest territories. When designing the method, four dimensions were identified in science, technology and innovation (STI) that define this potential as well as ten assessment criteria. The wild foods chosen for applying the method were
Alibertia patinoi
(a fruit commonly known as Borojó) and
Proechimys semispinosus
(Mouse of thorns), which are two of the main wild foods traditionally used by human communities in a tropical forest territory in the northwest of Colombia. In both cases, although there are significant advances in STI, compliance with some criteria is still required to regard them as viable alternatives for nutrition and food security within this territory. This research is useful for promoting the inclusion of wild food in food security programmes for communities where this food is already included in their traditional pattern of consumption and identifies the progress needed in STI to achieve this purpose. It may also promote the early recognition of possible traditional and cultural practices with high risk of transmission of pathogenic elements by the handling and/or inadequate consumption of wild foods. This early recognition could contribute to the prevention of diseases of wild animal origin, including those of rapid global spread.
Abstract
Three novel 19‐
nor
‐1α,25‐dihydroxyvitamin D
3
derivatives modified at C1 and/or C3 with an amino group were synthesized to study the influence of the substitution of one or both hydroxyl ...groups of A‐ring by amino groups on the affinity for vitamin D receptor (VDR) and vitamin D binding protein (hDBP), and also on the antiproliferative activity. The A‐ring precursors were prepared from
cis
,
cis
‐1,3,5‐cyclohexanetriol applying a desymmetrization reaction of a prochiral 1,3‐diol catalyzed by
Pseudomonas cepacia
lipase as a key step. The structural elucidation of diastereoisomers were unambiguously assigned by NMR spectroscopy.
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